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Science 9 Final Review Sheet
1. What does WHMIS stand for? (p12)
Workplace Hazardous Materials Information System
2. *Know the WHMIS symbols on p12-13.
3. *What is matter? (p16)
Anything that has mass and volume
4. *What is energy? (p504)
Something that can cause motion or do work
5. *What is mass? (p16)
Mass is the amount of material or substance in an object (commonly thought of as that which gives weight).
6. *What is volume? (p16)
Volume is the space an object takes up (commonly thought of as an object’s size)
7. *What is a chemical change? (p17)
A chemical change is a change in which when new substances are formed.
8. *What is a physical change? (p18)
A physical change is a change in which a new form of the same substance is formed.
9. *What are the three common state of matter on earth? (p18)
Solid, liquid and gas
10. *What state of matter completely takes up the volume of the container it is put in? (p18-19)
The gaseous state
11. *What are the 4 main ideas of the Kinetic Molecular Theory? (p19)
1. All matter is made up of very small particles
2. There is empty space between these particles
3. Matter’s particles are constantly moving. In solids they vibrate around fixed points, in liquids they
slide past each other but are attracted to each other, and in gases they move very far apart and very
fast
4. Adding energy (heat) makes particles move faster and farther apart while removing energy (heat)
makes particles move slower and closer together
12. *What is the change of state called when a solid changes directly into a gas? (p21)
sublimation
13. *What is the change of state called when a liquid changes directly into a solid? (p21) freezing or
solidification
14. *What is the change of state called when a gas changes directly into a liquid? (p21)
condensation
15. *What is the change of state called when a gas changes directly into a solid? (p21)
deposition
Science 9 Final Review Sheet
16. *What is the change of state called when a solid changes directly into a liquid? (p21) melting
17. *What is the change of state called when a liquid changes directly into a gas? (p21)
evaporation or vaporization
18. *How is a liquid different from a solid in shape and volume? (p19-20)
A liquid has no definite shape.
19. How are gases and liquids similar in shape and volume? (p19-20)
They both have shapes that are determined by their surroundings.
20. *How are solids and gases different in the amount of space between particles? (p19-20)
Solids have particles that are very close together while gases have particles that are very far apart.
21. *In what two ways does heat affect the particles of a substance? (p19-20)
Heat causes the particles of a substance to move faster and farther apart.
22. *As the particles of a gas lose heat, what changes do they go through? (p20-21)
The particles slow down and come close enough so that they attract each other and form a liquid. As the
particles slow even more they come closer together and form a solid in which they just vibrate.
23. *In general, what are physical properties of a substance? Give 4 examples of physical properties.
(p22)
Physical properties are properties that an object has all by itself like colour, hardness, density, electrical
conductivity, malleability, crystallinity
24. What is malleability? (p22)
Malleability is how well a substance can be beaten into sheets.
25. What is the difference between qualitative and quantitative properties? (p22)
Quantitative properties can be measured with numbers while qualitative properties can not. For iron, its
density is 7.8 g/cm3 (a quantitative property) and its colour is grey (no number for grey).
26. *In terms of molecules (the particles of a substance), how are pure substances different from impure
substances? (p23)
Pure substances have all their particles alike while impure substances have different kinds of particles.
27. *How is an element different from a compound in terms of its molecules? (p23)
Science 9 Final Review Sheet
The particles (molecules) of an element all have the same kind of atom while the molecules (particles) of a
compound have different kinds of atoms in their molecules (and their molecules are all alike).
28. What word did the Greeks use that referred to the smallest piece of a substance that could not be cut
into any smaller piece? (p28)
Atomos which today we call an atom
29. What was the main goal of the alchemists? (p29)
Alchemists were trying to turn lead and other ordinary materials into gold. They were also trying to find the
secret to eternal life. They were looking for an imaginary Philosopher’s stone to do these things.
30. *John Dalton in 1824 published his ideas about atoms. What was an atom like according to John
Dalton? (p29)
Dalton thought an atom was a hard indivisible particle
31. *What are the 4 main ideas of Dalton’s Atomic Theory? (p30)
1. All matter is made up of small particles called atoms
2. Atoms can not be created, destroyed or divided into smaller particles
3. All atoms of the same element are identical in mass and size and are different from the atoms of other
elements
4. Compounds are created when atoms of different elements link together in definite proportions (a
certain number of atoms of one element with a certain number of atoms of another element).
32. *J.J. Thompson in 1897 discovered currents of negative particles. What did he call these particles?
(p30)
electrons
33. *J.J. Thompson decided that Dalton’s idea of the atom was incorrect. What was the atom like
according to Thompson?
Thompson thought that atoms were soft with tiny hard particles (the electrons) in them much like a raisin
bun or a plum pudding is soft with particles in them.
34. What is meant by the term, model, when referring to a model of the atom? (p30)
A model is a mental picture of what a scientist thinks a certain thing is like.
35. *What did Rutherford discover in his gold foil experiment?
Rutherford discovered that positive alpha particles bounced back from gold atoms in a thin gold foil.
36. *Rutherford’s experiment showed that Thompson’s model of the atom was false. Explain why.
(p31)
If atoms were soft, why would alpha particles bounce back from these soft atoms? There must be something
solid in atoms that would bounce back alpha particles.
37. *What was the atom like according to Rutherford? (p31)
Rutherford thought that the atom had a small, solid centre that was positive. He called this small positive
centre the nucleus of the atom.
38. *What is the nucleus of the atom and where is it found? (p31,506)
The nucleus is found in the centre of the atom. It is a small, hard centre that is positively charged.
Science 9 Final Review Sheet
39. *How is a proton different from a neutron? (p31)
A proton has a positive charge while a neutron has no charge. They both have about the same weight.
40. What did Bohr discover about how electrons are arranged in atoms? (p31-32)
Bohr discovered that the electrons of an atom are arranged in specific energy levels or “shells” around the
nucleus an atom.
41. *What three parts are atoms made up of? (p32)
Atoms are made up of protons, electrons and neutrons.
42. *How much heavier are protons and neutrons than electrons? (p32)
Protons and neutrons are about 1800 times more heavy than electrons.
43. *What are the charges that are on electrons, protons and neutrons? (p32)
Electrons have negative charges, protons have positive charges and neutrons have no charge.
44. *Most of the volume of an atom is taken up by what particle as it moves around? (p33)
The volume or size of an atom is mostly taken up by moving electrons
45. What particles of an atom are fixed in place? (p33)
Protons and neutrons are fixed in place in the nucleus.
46. *What particles of an atom move about? (p33)
Electrons in an atom move around.
47. *What charge does a nucleus have? Why? (p33)
The nucleus has a positive charge because it has protons in it which have a positive charge and also neutrons
but they have no charge.
48. *Most of the weight of an atom is caused by what particle(s)? (p33)
Most of the weight of an atom is caused by neutrons and protons, the nucleus.
49. *If a chemical symbol has two letters, are both letters capitalized? (p43)
No, just the first letter is capitalized, like Fe or Ag
50. The element iron has the symbol Fe rather than I or Ir. Explain why. (p44)
Iron was known by the Romans as ferrum (Latin) so the symbol is Fe.
51. List 3 properties (chemical or physical) of sodium that are different from the properties of iron. (p45)
Sodium has a lower density than water (floats in water). Sodium reacts strongly with water releasing
hydrogen gas. Sodium produces a very strong base, sodium hydroxide (an alkali), when it reacts with water.
52. *What percentage of our atmosphere is composed of oxygen? (p45)
21% of our atmosphere is oxygen
53. What is the source of the oxygen in our atmosphere? (p45)
Plants, especially microscopic algae, are thought to have produced all the oxygen in our atmosphere.
54. Who was the first person to develop the periodic chart of the elements?
Science 9 Final Review Sheet
Mendeleev
55. How was the periodic chart useful for chemists? (p52)
It helped them to discover new elements and to look for a reason why elements form families.
56. *What does the atomic number of an element represent or stand for?
The number of protons the atoms of that element have.
57. The atomic mass of an element is a decimal number rather than a whole number. Why is this so?
(There is one key word in the sentence defining Atomic mass – p53)
Atoms of one element may differ slightly in their weights (number of neutrons) so averaging these various
weights in a sample of an element often produces decimal numbers.
58. *What is the ion charge of an element?
This is the electric charge that forms on an atom when it gains or loses electrons.
59. *What are the three kinds of elements found in the periodic chart? (p55)
Metals, non-metals and metalloids.
60. *What is a metalloid element?
A metalloid is an element that has some metallic properties and some non-metallic properties.
61. Write the symbols for 6 alkali metal elements.
Li, Na, K, Rb, Cs, Fr
62. *Indicate two physical properties and two chemical properties of alkali metal elements. (If not in the
text, google these)
Alkali metals are silver in colour. They are soft. They have density less than 1 which is why they float in
water. They react quickly with oxygen in air to form white powders. They react strongly with water to
produce hydrogen gas and very strong bases (alkalis).
63. Write the symbols for 6 alkaline earth elements.
Be, Mg, Ca, Sr, Ba, Ra
64. *Indicate one physical property and one chemical property of alkaline earth elements. (If not in the
text, google these)
Alkaline earth metals will burn in air, some producing bright colours that are used in fireworks. Alkaline
earth metals are silver in colour and have a density greater than 1 (they sink in water).
65. Write the symbols for 5 halogen elements.
F, Cl, Br, I, At
66. *Indicate one physical property and one chemical property of halogen elements. (If not in the text,
google these)
Halogens are very corrosive with metals, reacting strongly with them. They kill bacteria and in strong doses
will kill persons. They are irritating to eyes and noses. Two are gases, one a liquid and one a solid at room
temperature.
Science 9 Final Review Sheet
67. Write the symbols for 5 noble gas elements.
He, Ne, Ar, Kr, Xe, Rn
68. *Indicate one physical property and one chemical property of noble gas elements. (If not in the text,
google these)
The Noble gases are all gases at room temperature. They are not reactive with any of the elements or with
themselves.
69. *Where on the periodic chart do you find the (see p 54)
a. Metals?
Most of the chart, left of the stepped line
b. Non-metals?
To the right of the stepped line
c. Metalloids
On either side of the stepped line
70. Which has more protons, an atom of sodium or of potassium? (p54)
Potassium has 19 while sodium has 11
71. Which has more mass, an atom of gold or lead? (p54)
Lead has a mass of 207.2 while gold has a mass of 197.0
72. The unit for atomic mass is the amu. What does each letter stand for? How many amu does a proton
or neutron have? (p53)
Atomic Mass Unit. One amu is 1.66 x 10-27 kg g. A proton or neutron weighs 1 amu.
73. *What particle has to be removed for a neutral atom to become a positive ion?
When an electron is removed from a neutral atom it becomes a positive ion.
74. *Metal elements all tend to become what kind of ion? (positive, negative or neutral?) (p54)
Metal atoms become positive ions.
75. *Non-metal elements all tend to become what kind of ion? (positive, negative or neutral?) (p54)
Non-metal atoms become negative ions.
76. When an element has an ion charge of zero (see the noble gas family) what does that tell you about
the element? (p54)
An element with an ion charge of zero will not form ions, will not gain or lose electrons.
77. What are the three ion charges that manganese can have? (p54)
2+, 3+, 4+
78. *What are the vertical columns called in the periodic chart? (p59)
Vertical columns are called chemical families.
79. *What are horizontal rows in the periodic chart called? Google this
Horizontal rows are called periods.
Science 9 Final Review Sheet
80. *How many electrons can there be in each of the first four shells surrounding an atom?
2,8,8,8
81. *Draw a simple Bohr model diagram for the following elements
a. Hydrogen has 1 electron on the innermost circle
b. Lithium has 2 electrons on the innermost level and 1 electron on the next level
c. Sodium has 2 electrons on the innermost level, 8 electrons on the next level and 1 electron on
the third level
Potassium has 2 electrons on the innermost level, 8 electrons on the next level, 8 electrons on
level three and 1 electron on level 4
82. *List the number of valence electrons in atoms from each of the following chemical families:
a. Alkali metals
Alkali metals all have 1 valence electron
Science 9 Final Review Sheet
b. Alkaline earth metals all have 2 electrons
c. Halogens
Halogens all have 7 valence electrons
d. Noble gases
Helium has 2 valence electrons but all other noble gases have 8 valence electrons.
83. On the periodic table on page 54, locate the metalloid with the lowest atomic number. What is its
name and symbol?
Aluminum atomic number 13
84. *Draw a Bohr model diagram for atoms of each of the following elements:
a. Carbon has 2 electrons on the first level, 4 electrons on the second level
b. Fluorine has 2 electrons on the first level, 7 electrons on the second level.
c. Magnesium has 2 electrons on the first level, 8 electrons on the second level, 2 electrons on
the third level.
d. Sulphur has 2 electrons on the first level, 8 electrons on the second level, 6 electrons on the
third level
Science 9 Final Review Sheet
85. What is an electron shell?
An energy level that has a maximum number of electrons it can hold.
86. How many electrons are in each shell in an atom of argon?
Argon has 2 electrons on the first level, 8 electrons on the second level, 8 electrons on the third level
87. *Do metals lose or gain electrons as they form ions?
Metals lose electrons
88. *Do metals form negative ions or positive ions?
Positive ions
89. *Do non-metals lose or gain electrons as they form ions?
Non-metals gain electrons
90. *Do non-metals form negative ions or positive ions?
Negative ions
91. Is the electron arrangement in a sodium ION similar to neon or argon?
neon
92. Is the electron arrangement in a chlorine ION similar to neon or argon?
argon
93. Explain the difference between a valence electron and a valence shell.
A valence shell is the outermost energy level of an atom. A valence electron is one electron in the outermost
shell of an atom.
94. *What is similar about the electron arrangements of all the alkaline earth metals?
They all have the same number of outermost electrons
95. *What feature of the electron arrangement in noble gases causes them to be chemically unreactive?
Noble gases all have full shells so they don’t want to lose or gain electrons.
96. *How can a neutral metal atom achieve noble gas stability?
It can lose electrons so that it gets a full outer energy level.
97. *How can a neutral non-metal atom achieve noble gas stability?
It can gain electrons so that it gets a full outer energy level.
98. *Draw a Bohr diagram for each of the following atoms:
a. Ne has 2 electrons on the first energy level, 8 electrons on the second energy level.
Science 9 Final Review Sheet
b. S has 2 electrons on the first level, 8 electrons on the second level, 6 electrons on the third
level
c. K has 2 electrons on the first level, 8 electrons on the second level, 8 electrons on the third
level, 1 electron on the fourth level
d. Be has 2 electrons on the first level, 2 electrons on the second level
99. *Use the Bohr model diagram below to answer the following questions. This diagram shows the
number of electrons, but not the number of protons.
Science 9 Final Review Sheet
a. If this diagram represents an atom, not an ion, what element is it?
This is neon with 10 electrons and 10 protons.
b. If this diagram represents an ion with a charge of 3- , what element is it?
Nitrogen, N-3 , which has 7 protons and 10 electrons
c. If this diagram represents an ion with a charge of 2+ , what element is it?
Magnesium, Mg+2 , which has 12 protons and 10 electrons
100.
*Draw a Bohr model diagram for each of the following atoms or ions:
a. Ar has 2 electrons on the first level, 8 electrons on the second level, 8 electrons on the third
level
b. P and P3- P has 2 electrons on the first level, 8 electrons on the second level, 5 electrons on
the third level. P has 2 electrons on the first level, 8 electrons on the second level, 8 electrons
on the third level
c. S and S2- S has 2 electrons on the first level, 8 electrons on the second level, 6 electrons on
the third level. S-2 has 2 electrons on the first level, 8 electrons on the second level, 8
electrons on the third level
d. Cl and Cl- Cl has 2 electrons on the first level, 8 electrons on the second level, 6 electrons on
the third level. Cl-1 has 2 electrons on the first level, 8 electrons on the second level, 8
electrons on the third level
Science 9 Final Review Sheet
e. K and K+ K has 2 electrons on the first level, 8 electrons on the second level, 8 electrons on
the third level, 1 electron on the fourth level. K+1 has 2 electrons on the first level, 8 electrons
on the second level, 8 electrons on the third level
f. Ca and Ca+2 Ca has 2 electrons on the first level, 8 electrons on the second level, 8 electrons
on the third level, 2 electrons on the fourth level. Ca+2 has 2 electrons on the first level, 8
electrons on the second level, 8 electrons on the third level
101.
What do you notice about the arrangement of electrons of the ions in parts (b) to (f) of
question 21 above?
The ions all have the same number of outer and inner electrons.
102.
Name two ways in which elements can combine into compounds.
Elements can form ionic compounds or covalent compounds.
103.
*How are atoms connected to each other in covalent compounds?
Atoms share electrons in covalent compounds
104.
CO2
105.
*Give one example of a covalent compound. (Non-metal + non-metal)
*Give one example of an ionic compound. (Metal + non-metal)
Science 9 Final Review Sheet
MgCl2
106.
What needs to happen to atoms of different elements to allow them to combine to form an
ionic compound?
They must give and receive electrons or they must share electrons
107.
What is the meaning of the prefix, “poly” in the term, “polyatomic ion”?
It means many as in many atoms joined together with a charge
108.
How are the atoms in a polyatomic ion connected together?
In a polyatomic ion the atoms are linked together by covalent bonds.
109.
What kind of bond can a polyatomic ion form in a compound?
Polyatomic ions form ionic bonds with other elements or polyatomic ions.
110.
Give the name and formula of the polyatomic ion used in some roadside-check equipment that
tests for alcohol on drivers’ breath.
111.
Give one example of how the polyatomic ion, ammonium, is used.
Ammonium is joined to nitrate to form an ingredient of fertilizer.
112.
*What is a chemical bond?
A chemical bond is an attraction between opposite ions or shared electrons.
113.
*What are the two kinds of compounds?
Ionic and covalent compounds
114.
*How are two atoms held together in a covalent bond?
Atoms in covalent compounds are held together by one, two or three pairs of shared electrons.
115.
*What causes ions to come together in an ionic compound?
The opposite charges
116.
When sodium and chlorine combine, one electron transfers from each sodium
atom to
each chlorine atom. Explain why the new ions of sodium and chlorine will arrange themselves into
an alternating fashion inside a crystal lattice.
Since + ions attract to – ions, every + attracts a number of – ions and each – ion likewise attracts a
number of – ions around it to form an alternating crystal lattice.
117.
When lithium reacts with fluorine, one electron transfers onto a fluorine atom, forming ions.
Which ion has a positive charge, and which ion has a negative charge? Write the symbol for each
ion.
Lithium loses 1 electron to become Li+1` and fluorine gains 1 electron to become F-1
118.
*In a water molecule, how many atoms are connected directly to each oxygen atom? To each
hydrogen atom?
Science 9 Final Review Sheet
Two atoms are connected to each oxygen atom and 1 atom is connected to each hydrogen atom.
H (H2O)
H—O—
119.
What is the name and formula of the polyion present in eggshells as well as teeth.
Ca3CO3 , calcium carbonate
120.
What is the name and formula of the polyion present in your bones?
Ca3(PO4)2 , calcium phosphate
121.
What is the name and formula for each of the two polyions that has the element nitrogen (one
is positive and one is negative)?
Nitrate, NO3 -1 ,Ammonium , NH4+1
122.
For the polyion, phosphate, PO4 -3 (picture on page 80), what kind of bond holds each oxygen
atom to the phosphorus atom?
Covalent bond
123.
For the polyion, phosphate, PO4 -3 (picture on page 80), how many atoms does the phosphorus
atom connect to?
four
124.
What is the general term used to describe the ion, phosphate, PO4 -3 (picture on page 80)?
Polyatomic ion
125.
Ionic compounds melt at high temperatures. For example, table salt is an ionic compound that
melts at 800 C. Why is it so difficult to melt ionic compounds?
Ionic bonds are very strong and take lots of energy to break.
126.
In a compound that contains a polyatomic ion, there are both covalent and ionic bonds.
Where are the covalent bonds, and where are the ionic bonds? (See example of calcium carbonate
below.
Covalent bonds hold the atoms in a polyion together but ionic bonds hold polyions to other elements or other
polyions.
127.
How many oxygen atoms are connected to each chromium atom in the dichromate ion?
Science 9 Final Review Sheet
Each chromium atom is connected to 4 oxygen atoms
128.
*Be able to write chemical formulas and names like in chapter 3.2
129.
In a natural gas fireplace, the Natural gas combines chemically with the oxygen gas. The new
substances made in this reaction are carbon dioxide and water. Identify the reactants and products in
this reaction.
The reactants are natural gas (methane-CH4 and oxygen (O2). The products are carbon dioxide and water
130.
*Identify each of the following processes as mainly chemical change or a physical change:
a. Boiling water
Physical change
b. Tearing clothes
Physical change
c. Rusting of a nail
Chemical change
d. Lighting a match
Chemical change
131.
*Identify each change below as a chemical or physical and as endothermic or exothermic:
a. Melting an ice cube
Physical change (endothermic)
b. Burning a candle
Chemical change (exothermic)
c. Grinding up sea salt
Physical change (endothermic)
d. Rain turning to snow
Physical change (exothermic)
132.
*Name two kinds of change that can affect matter
Physical and chemical changes
133.
*Which kind of change involves the breaking of bonds between atoms?
Chemical change
134.
*Which kind of change involves only changes to the appearance of a substance?
Physical change
Science 9 Final Review Sheet
135.
*Give one specific example of a change that produces new substances with new properties.
Burning a match
136.
*Give one specific example of a change that changes a substance without producing a new
substance.
Breaking a piece of glass
137.
*When a sodium metal burns in oxygen gas it gives off a brilliant white light and a white
solid forms.
a. Identify the reactants and the product.
The reactants are the sodium and oxygen. The product is the white solid, sodium oxide
b. State whether this reaction is exothermic or endothermic.
The reaction is exothermic because energy is given off into the surroundings
138.
*Lots of chemistry happens in the kitchen, including sometimes, the making of curry. A
simple curry involves the frying of onions and garlic together and then adding curry spices. Keeping
this in mind, decide whether each step below is primarily a chemical change, a physical change, or a
mixture of both.
a. Slicing onions and crushing garlic
Mainly a physical change
b. Getting onion vapour in your eyes (causes stinging and tears)
Mainly a physical change
c. Frying onion slices and garlic in vegetable oil
Mainly a chemical change
d. Stirring curry spices into the fried portions
A mixture of physical and chemical changes.
e. Tasting the curry to check the flavour
A mixture of physical and chemical changes.
139.
*Each of the following involves both chemical and physical changes. Identify both in each
of the examples.
a. Flattening a flower in a book and leaving it there for a few weeks
Liquids evaporate-physical change. Flower colours change-chemical change
b. Leaving a banana to become overripe and then decompose
Gases escape-physical change. Colour blackens-chemical
c. Baking bread
Liquids become solids, water evaporates-physical. The bread ingredients change with
baking-chemical (not reversible)
140.
*Explain why liquid water changing into steam is a physical and not a chemical change.
Steam is still water but just in the form of a gas
Science 9 Final Review Sheet
141.
A white crystal is ground up into a fine powder and then placed into a beaker full of water.
The mixture is stirred until the white powder disappears. After two weeks, the water is gone and a
number of white crystals are crusted onto the inside of the beaker. Make a brief list of the physical
and chemical changes that occurred.
Grinding is a physical change. Dissolving is a physical change if no new substance
forms. Evaporating water is a physical change. Forming new white crystals is a
physical change if the substance is the same as before or a chemical change if it is new.
142.
*Two clear and colourless solutions are mixed together and stirred. Almost immediately,
the mixture becomes cloudy white. After a while, a white powder settles out on the bottom of the
beaker. Explain whether the process of forming a white powder was likely to be a physical change or
a chemical change.
This is likely a chemical change since something that won’t be dissolved has formed
from two things that were dissolved.
143.
*What is the function of a cell membrane?
The cell membrane controls what enters and leaves the cell.
144.
*Describe the structure of a cell wall.
The cell wall is a tough and rigid structure surrounding the plant cell membrane. It is composed of cellulose.
145.
*What is an organelle?
An organelle is a part of a cell that has some specific job or function.
146.
*What is the function of mitochondria?
Mitochondria perform the process of respiration. They take in glucose and oxygen and burn them to release
the energy in glucose for the cell to perform all its functions.
147.
*What is the function of a ribosome?
A ribosome manufactures proteins.
148.
*Where do proteins go after they are made on the endoplasmic reticulum?
Proteins from the E.R. are sent to the Golgi Body where they are modified and packaged to be sent out of the
cell.
149.
*What is the function of the nucleus?
Science 9 Final Review Sheet
The nucleus controls the growth and development of the cell.
150.
*What are the parts of the DNA molecule?
DNA is made up of nitrogen bases, phosphates and sugars.
151.
*Describe how bases pair up in the DNA molecule.
In DNA, A pairs up with T and G pairs up with C.
152.
*What is chromatin?
Chromatin is the substance that makes up chromosomes. It is composed of DNA and protein.
153.
*How many chromosomes does a human body cell contain?
The human body contains 46 chromosomes, 23 pairs.
154.
*What are genes?
Genes are small parts of a strand of chromatin or of a chromosome that make a certain trait of an organism.
Each gene actually has a code that makes a particular protein.
155.
*Where are genes located?
Genes are located on chromosomes (chromatin). They are from hundreds to thousands of bases long.
156.
*Your retina cells (at the back of the eye converting light energy into electrical impulses) and
muscle cells (shrink in length when stimulated) contain identical DNA. How are these cells able to
function differently?
Different sections of DNA become active and are used to make different proteins in retina cells as compared
to muscle cells.
157.
*What must occur before a new protein is made in the cell?
A segment of DNA in chromatin makes an RNA copy of itself. This RNA copy goes from the nucleus to to
the cytoplasm where it links to ribosomes. The ribosomes use the RNA copy to build a unique protein
according to the RNA code.
158.
*What is RNA?
RNA is a molecule both similar to and different from DNA. It copies the DNA base code and moves to the
cytoplasm where gets used by ribosomes to make a protein according to the RNA code.
159.
*How is the message carried from the nucleus to the ribosomes?
RNA carries the DNA code for what protein to make to the ribosomes in the cytoplasm where the ribosomes
follow the RNA copy’s instructions .
160.
*What happens to a protein once it is made?
A protein made by ribosomes on the E.R. is exported out of the cell while a protein made by free-floating
ribosomes is used within the cell. Any protein can be used for the cell’s structure or for its functions (to do
special jobs).
161.
*What is the function of the Golgi body?
The Golgi body modifies proteins sent to it from the E.R. and puts membrane packages around those
modified proteins which then get sent out of the cell.
Science 9 Final Review Sheet
162.
*Identify the job or function of the structure below:
The Golgi body modifies proteins and puts membrane packages around them.
163.
*Identify the job or function of the structure below:
The chloroplast performs the process of photosynthesis. It captures sunlight energy and stores it in a sugar it
makes, glucose, made from carbon dioxide and water.
164.
*Identify the job or function of the structure below:
The nucleus controls the growth and development of a cell.
165.
*Identify the job or function of the structure below:
The mitochondrion performs the process of respiration. It burns glucose by using oxygen and releases the
energy from glucose so the cell has energy to do all its life processes.
166.
Draw a diagram that shows the relationship between a chromosome and a gene.
A gene is a small part of a chromosome. There are thousands of genes on a chromosome.
167.
*What do the genes in a cell do? What is their function?
Science 9 Final Review Sheet
Genes cause the development of certain traits or features in an organism. Specifically, a gene causes the
production of a certain protein. What proteins get made determine what a cell changes into.
168.
How is the information contained in the DNA transported out of the nucleus?
The DNA information (code) is copied into RNA and then RNA moves out the nuclear pores into the
cytoplasm to ribosomes.
169.
*Where are the ribosomes located that manufacture proteins for transport out of the cell?
Ribosomes on E.R. make proteins that are transported out of the cell.
170.
*Why is the Spirit Bear white?
A gene mutated (the DNA bases were changed) and this caused a protein change which made the bear’s coat
white.
171.
*What is a gene mutation?
A gene mutation is a change in the order of the DNA bases which causes a new protein to be made.
172.
*What is the difference between a neutral mutation and a negative mutation?
A neutral mutation is a body change that has no effect on the survival of the organism. A negative mutation
is a body change that harms an organism.
173.
*How do viruses cause mutations?
When viruses insert their DNA into an organism, they may damage or change genes in the organism.
174.
Given the normal DNA sequence ACTGGTACTGTTA, identify each of the following as a
substitution, loss, or addition of a base.
a. ACTGCTACTGTTA
This a substitution of C for the base G.
b. ACTGGTACTGTT
This is a loss of the A.
c. ACTGGGTACTGTTA
This is an addition of the base G.
175.
*What are the three different effects a mutation can have on an individual?
A mutation may be neutral, positive or negative.
176.
Give an example of a positive mutation.
The mutation making persons immune to AIDS or the mutation causing the modern wheat plant are both
positive mutations.
177.
What is the effect of the mutation in sickle cell anemia?
The sickle cell mutation has a negative effect, except in certain parts of the world where it semi-protects
against the disease, Malaria.
178.
Why is the white coat colour of the Spirit Bear considered to be a neutral mutation?
The white coat of the Spirit Bear neither helps or hurts its survival in the wild.
Science 9 Final Review Sheet
179.
*What can happen when a mutated gene makes a protein that doesn’t function properly?
Provide an example.
If a mutated gene makes a defective protein, some vital job may not happen. In sickle cell anemia, defective
hemoglobin changes its shape in low oxygen and threatens the life of an organism.
180.
Mutations to DNA cause changes in organisms. Explain why this might be important to the
survival of a species.
If mutations (changes) happen regularly, then beneficial or positive ones may help a species to survive better.
181.
Predict whether a mutation in a human skin cell that results in cancer can be passed on to an
offspring.
A mutation in a human skin cell can NOT be passed on to offspring because only sperm and egg cells pass
on information and mutations.
182.
Examine the photographs below.
a. Which cell is the mutated cell?
The left cell is a mutated sickle cell.
b. How do you know?
The irregular sickle shape
c. What disease is caused by this mutation?
Sickle cell anemia
d. Explain how this mutation is a negative mutation.
Sickle cells get stuck in capillaries and block blood flow which can damage organs like lungs, kidneys and
liver.
183.
*Why is it important to be protected with a lead shield when you are getting dental X rays?
X rays can cause mutations. If reproductive cells (in ovaries or testes) get exposed to X rays, future children
may have defective genes so these parts of the body are covered with protective lead shields.
184.
*Why can sun tanning be dangerous for a skin cell?
Sun tanning exposes the skin to more UV radiation which can cause mutations leading to skin cancer.
185.
How can viruses cause mutations?
When a virus inserts its DNA into a host cell, it can change the DNA order of the host’s cell which can cause
the production of new proteins, quite possibly defective ones.
186.
*In the diagram below, identify which part is the phosphate, the sugar, and the base.
Science 9 Final Review Sheet
Parts a and d above are the nitrogen bases. Part b above is a sugar. Part c above is a phosphate.
187.
Draw a nucleus and label the nuclear membrane, nuclear pores and chromatin.
188.
*Explain how the nucleus controls the functions of life.
The code of the DNA in the chromatin (chromosomes) determines the RNA copy which tells the ribosomes
what kinds of proteins to make. DNA code  RNA copy code  Specific Protein
189.
*What makes the structure and function of a skin cell different from a nerve cell?
The kinds of protein that get made in a skin cell are different than in a nerve cell. This happens because
different parts of the DNA get activated in these two kinds of cell.
190.
The protein hemoglobin, which carries oxygen in red blood cells, is not made in a skin cell.
Explain why.
In a skin cell, different parts of the DNA in the nucleus get activated which makes different RNA and thus
different proteins.
191.
*One side of a DNA molecule contains the following sequence of bases:
ACCTGCTAT
Write the sequence of bases on the other side of the molecule.
TGGACGATA
Science 9 Final Review Sheet
192.
In which part of the DNA molecule would a change be more damaging to the cell: in the
sugar-phosphate sides of the molecule or in the A,G,C,T bases? Explain.
A cell would be damaged more by a change in the bases (A,G,C,T) because the base order is a code that
causes a specific protein to be made. Different proteins cause cells to develop differently.
193.
Explain why DNA cannot leave the nucleus.
The cell needs to constantly refer to DNA instructions as it grows and develops. The DNA is like a library
of information about what the cell needs to do. It is important that this DNA information does not leave the
nucleus and get lost.
194.
*Explain why the skin cells of an adult must divide.
Skin cells must divide to make new cells to replace those that are lost continually through abrasion (rubbing).
195.
*List the three stages of the cell cycle.
Interphase, mitosis and cytokinesis
196.
*What are the events that take place during interphase?
The cell grows, makes new molecules and organelles, and makes copies of each DNA strand.
197.
*Why is DNA replication so important?
The DNA must be exactly copied (replicated) so that each new cell from division can have an exact,
complete set of chromatin like the original cell had.
198.
*What does DNA look like at the end of interphase?
The DNA is loosely coiled at the end of interphase with each chromatin strand having a copy of itself
attached to it at a spot called the centromere.
199.
How does the cell prepare for cell division?
The cell copies each DNA strand (chromatin fiber) and they loosely coil up. The organelles are also copied
so that the cell contents have doubled.
200.
*What are the phases of mitosis?
Prophase, metaphase, anaphase, telophase.
201.
*What do the nucleus and chromosomes look like during prophase?
During prophase, the nuclear membrane disappears and the chromatin fibers (DNA strands) coil up into
bodies called chromosomes which become visible and attach themselves to a fiber network called the spindle
that forms during prophase.
202.
*How does cytokinesis differ in plant and animal cells?
In plant cells, a cell plate or wall forms between the two daughter cells. In animal cells, the two daughter
cells pinch apart.
203.
*Outline the activities in the cell at each of the following phases of interphase:
a. Growth and preparation
The cell increases in size, making new proteins and making copies of its organelles.
b. Replication
Science 9 Final Review Sheet
The cell makes a copy of each DNA strand so that there are now two DNA strands that are identical to the
original DNA strand.
204.
*List the steps in DNA replication.
The DNA molecule opens up (“unzips itself”). New nitrogen bases (connected to sugars and phosphates)
pair up with their complementary bases making two new identical strands.
205.
*What is the function of mitosis?
Mitosis makes new cells (“daughter cells”) identical to the original cell (“mother cell”) that divided. This
process makes an organism grow and is also used to repair body regions that are damaged.
206.
*Is mitosis constantly occurring in your cells? Explain.
Mitosis is NOT constantly occurring in cells. It only happens in cells that are producing growth - like the
cells at the bases of hairs or cells in the stomach lining (replaced every 3 days) or lower skin layers or in the
bone marrow making new blood cells.
207.
*What is the function of the spindle fibers?
Spindle fibers help to pull duplicate chromosomes to opposite ends (“poles”) of the cell.
208.
*Use the diagrams below to answer questions below.
a.
.
b.
c.
A. Which diagram shows a cell at the beginning of anaphase?
d.
a
B. Which diagram shows a cell with sister chromatids moving to opposite poles?
a
C. Which diagram illustrates a cell where a new nuclear membrane is forming?
d
D. Write down the correct sequence of letters to show the phases of mitosis from beginning to
end.
c, b, a, d
E. Using only two of the above diagrams, explain how you could tell whether a cell has just
completed mitosis or is entering (starting) mitosis.
If a cell is at stage d, making two new nuclear membranes, mitosis has just finished.
If a cell is at stage c, losing its nuclear membrane and making a spindle and having the chromosomes
become visible, mitosis has just started.
209.
*How is plant cell division different from animal cell division?
Plant cells do not have asters or centrioles (centrosomes) at the end of their spindles.
Plant cells form a cell plate to separate the cells while animal cells pinch apart.
210.
Why must the nuclear membrane break down for mitosis to occur?
Science 9 Final Review Sheet
The chromosomes need more space to separate themselves so the nuclear membrane breaks down allowing
the chromosomes the entire cell to arrange themselves along the middle (“equator”) of the cell.
211.
In interphase, the DNA is loosely coiled. Why do you think it is important that the DNA be
compact and tightly coiled during mitosis? (Hint: Think of an unraveled spool of thread.)
If chromatin stayed in the form of threads, they would get tangled up and could not be separated to opposite
ends of the cell. When they coil up and compact themselves, chromosomes are easily separated from each
other to opposite ends of the cell.
212.
What might happen if DNA replication and mitosis were not highly controlled?
If replication and mitosis were not highly controlled, irregular and perhaps cancerous growths would occur
all over in many celled organisms.
213.
*What are some environmental factors that can contribute to the development of cancer?
Radiation sources and mutagenic chemicals may damage DNA and if this damage occurs many times it may
lead to cells turning into cancer cells that are dividing out of control.
214.
*How is a cancer cell different from a normal cell?
Cancer cells do not stop dividing when they get a signal to stop dividing. Cancer cells grow in multiple
layers forming a tumour mass. Cancer cells have large, abnormal nuclei. Checkpoint proteins no longer
function in cancer cells. Cancer cells spread to other body locations through the lymph and circulatory
systems. Cancer cells have the ability to repair lost parts of chromosome telomeres which keeps them
dividing forever (past the normal 35 times). Many kinds of cancer cells have lost the apoptosis (cell suicide)
program that gets rid of defective cells.
215. *Summarize the events of interphase and mitosis (prophase, metaphase, anaphase and telophase p156157)
In interphase the cell grows to about double its size, it copies its chromatin (DNA) which is held together at
its centromeres (p156), it copies its organelles and the chromatin begins to coil up. In prophase, the cell’s
nucleoli and nuclear membrane disappears, a spindle made up of fibers starts to form (made by centrioles in
animal cells), chromatin fibers coil up and becomes visible as chromosomes, the chromosomes attach
themselves to the spindle with each copy chromatid attaching to a separate fiber of the spindle. In
metaphase, the spindle fibers tug at the chromosomes, lining them up in the middle of the cell. In
anaphase, the centromeres holding the copy chromatids together break and the spindle fibers pull the
chromatids to opposite ends of the cell. In telophase the spindle disappears, the chromosomes unwind to
become chromatin again, nuclear membranes form again around the chromatin and nucleoli also reappear.
216. *How does binary fission in bacteria differ from binary fission in eukaryotic cells?
Bacteria in binary fission just duplicate their single chromosome and split apart. They do not go through the
stages of mitosis like cells with nuclei (eukaryotic cells).
217.*How does budding in yeast cells differ from binary fission in amoebas?
When yeast cells bud, the cell divides by pushing out a smaller cell from a larger cell.
218.*What is fragmentation?
Fragmentation is when parts of an organism break off and then develop into new, complete organisms.
219.*What is plant grafting?
Science 9 Final Review Sheet
Plant grafting is when one plant part is attached to another plant. The attached plant part then grows on the
plant and becomes part of the other plant.
220.*Use the following KEY to answer the questions a-e below. KEY: A. binary fission B. budding
C. fragmentation D. vegetative reproduction E. spore formation
a. This reproduction begins as an outgrowth of the parent, then separates to become an
independent organism.
budding
b. This reproduction happens in bacteria.
Binary fission
c. This is a common reproduction method in the hydra.
budding
d. In this kind of reproduction, an animal grows from a piece that has separated from the parent.
fragmentation
e. This form of reproduction is often used to survive extreme conditions.
Spore formation
221.*Compare similarities (if there are any) and differences between budding and binary fission.
In many-celled organisms, budding involves mitosis making a cell mass that forms into a new organism
growing on the parent. Binary fission is happening only in bacteria and involves just the duplication of a
single chromosomes and then splitting the cell into two equal parts. In yeast budding, the chromosomes are
duplicated and one set pushes out of the cell into a smaller bud cell.
222.*List two multicellular organisms that reproduce by budding.
Sponges and hydras
223.List three ways that plants can reproduce asexually.
Plants can reproduce by fragmentation (Eurasian milfoil), by sprouts (potatoes), by making new bulbs, by
making runners, or by growing new, “baby plants” on stems or leaves.
224.*Explain why organisms that reproduce asexually often produce large numbers of offspring.
Often these organisms are food for others so to survive they reproduce in large numbers. They may also
reproduce in large numbers because the chances of getting an offspring to a suitable environment are low.
225.*How do some spores survive unfavourable conditions?
Some spores have tough outer coats that protect them from unfavourable conditions.
226.Explain why bacteria do not undergo mitosis.
Bacteria have just one chromosome so it just needs to be replicated and then the cell can divide. No spindle
or lining up is needed like in mitosis.
227.*How are embryonic human stem cells like plant cells?
Human stem cells can change themselves into any kind of cell like plant cells which reproduce asexually do
(Like growing roots on a stem cut off from a plant.).
228.Sea stars are able to attach to oysters, pry open their shells, and eat the insides. Oyster farmers once
tried to destroy sea stars by cutting them into pieces and throwing them back into the ocean. Predict
what happened and why.
Each piece of starfish became a new complete starfish and there were now more starfish than ever – all
eating the oysters.
Science 9 Final Review Sheet
229.Why do you think boaters are asked to clean weeds off their motors before entering, and after exiting
a water body?
Pieces of water weed may stay attached to the boat motor and survive long enough so that when the boat is
put into another lake these pieces break off and become entire new water weeds contaminating a new lake.
230.*What are the advantages of asexual reproduction?
Asexual reproduction is fast and can quickly provide large numbers of new offspring. Only a single parent
is needed to make many offspring.
231.*What are the disadvantages of asexual reproduction?
Asexual reproduction makes identical clone copies of the parent so if the parent has a health weakness, all
the offspring have the same weakness. Also, many times asexually produced offspring are formed near their
parents and end up competing with their parents for food and space.
232. *Be able to identify the stage of mitosis from pictures of cell division (see p156-157)
233.*What does the term, “genetic diversity”, mean?
It means that there are many differences between the individuals of a species or kind of organism.
234.*What is the function of meiosis?
Meiosis reduces the chromosome number in half and produces more genetic diversity.
235.*What is the haploid number of chromosomes in humans?
23 is the n number or haploid number
236.*What is the diploid number of chromosomes in humans?
46 is the 2n or diploid number
237. *What is another name for a fertilized egg?
Zygote
238.*What are homologous chromosomes?
Chromosome pairs from each of the parents. Each pair is the same kind of chromosome, one from the
mother and one from the father, and has genes for differing forms of the same traits (ex: hair colour or eye
colour).
239.*Compare the number of chromosomes in a human skin cell to the number of chromosomes in a
human egg cell.
A skin cell has 46 (diploid – 2n) while an egg cell has 23 (haploid -n)
240.*What characteristics could you use to identify a pair of homologous chromosomes?
The chromosomes would have the same size and shape and carry genes for the same traits (like eye colour).
241.*What are the benefits of genetic diversity?
Genetic diversity helps a population to survive better.
242.How does a zygote become an embryo?
A zygote divides by mitosis for many times .
243.*Fill in the following table. Complete the table comparing mitosis and meiosis.
Science 9 Final Review Sheet
Question
Where does it take place?
Mitosis
In all body cells
Meiosis
In ovaries and testes (gonads)
How many cells are produced?
2
4
What happens to the number of
chromosomes?
Stays the same
Is reduced in half
How do parent and daughter cells
compare genetically?
Daughter cells are identical to
parent (mother) cell
How do daughter cells compare
to each other genetically?
Daughter cells are identical to
each other
Daughter cells have half the
number of chromosomes and are
different genetically from the
parent (mother) cell
Daughter cells are different from
each other due to crossing over
and independent assortment
How many divisions of
chromosomes takes place
The purpose of this type of cell
division
1
2
Is needed for growth and repair
of an organism
Is needed for sexual
reproduction, to make a new
organism with a mix of features
from both parents
244.*What is the difference between chromosomes at the start of meiosis and mitosis?
In Meiosis, homologous chromosomes pair up to form groups of 4 called tetrads
245.Explain how crossing over can result in variation.
Crossing over causes different gene combinations on a single chromosome because pieces get exchanged
with its homologous partner chromosome.
246.Explain how independent assortment can result in variation.
In independent assortment, maternal and paternal chromosomes are randomly separated to the daughter cells
which means they now have a random mix of chromosomes from the father and from the mother.
247.Give an example of a type of chromosome mutation.
When a chromosome piece gets lost, a chromosome piece is inserted backwards, a chromosome piece is
added.
248.*Give an example of a genetic disorder.
Downs syndrome is caused by an extra chromosome number 21 in body cells. Downs syndrome persons
have 47 chromosomes instead of 46 in their body cells.
249.*Explain why meiosis is important for the survival of organisms.
Science 9 Final Review Sheet
Meiosis is necessary for the survival of a species (the next generation) because it reduces the chromosome
number to keep it the same from one generation to next. Without meiosis, reproduction would most likely be
impossible or highly problematic.
250.Draw a pair of homologous chromosomes before and after crossing over.
251.*A dog has 76 chromosomes
a. How many pairs of homologous chromosomes does it have?
38
b. How many chromosomes would be in each sperm cell of a dog?
38
253.What is the method of fertilization for land-dwelling animals?
Mostly internal fertilization
254.What is the method of fertilization for water-dwelling animals?
Both internal and external fertilization
255.*What is pollination?
Pollination is the moving of pollen from the anthers of a flower to the stigma of a flower (most often another
flower on another plant).
256.*What can be found inside a seed?
A food source (endosperm) and a tiny embryo plant.
257. What are two conditions that must be met for sexual reproduction to occur?
A sperm must meet an egg and it must be drawn into the egg and fuse with the egg’s nucleus.
Science 9 Final Review Sheet
258.Name and briefly describe the three stages of sexual reproduction.
A male and female organism must mate. Fertilization must occur which is when a sperm from the male
meets and fuses with an egg from the female. The fertilized egg then divides many times and develops into a
complete new organism.
259.*What is internal fertilization?
Internal fertilization is when sperm from a male is deposited inside the body of a female.
260.*What is external fertilization?
External fertilization is when sperm from a male is deposited on eggs outside the body of a female.
261.*Why is it important that only one sperm fertilizes an egg?
The fertilized egg must have only two chromosome sets (one from a single sperm and one from the egg), not
three or four which is what would happen if more than one sperm fertilized an egg.
262.Why is water or water-containing fluid necessary for animals that reproduce sexually?
Sperm need a fluid to swim in to get to the egg and also water is needed to keep sperm from drying up.
263.*What is the function of the pollen tube?
The pollen tube carries the sperm from the stigma to the ovary where the egg is.
Science 9 Final Review Sheet
264.*Describe one difference in how flowering plants and cone-bearing plants sexually reproduce.
One difference is that flowering plants have flowers that have colourful petals, nectar and scents that attract
pollinators while cone-bearing plants use wind for pollination and thus have no flowers, just male and female
cones. (red flowers attract birds like hummingbirds, blue&purple flowers attract bees, white flowers attract
moths and flowers open at dusk attract bats)
A second difference is that flowering plants develop a fruit around their seeds but cone-bearing plants
produce no fruit covering around their seeds.
Science 9 Final Review Sheet
265.*List the following stages of human development in order : blastula, zygote, fetus, gastrula, morula
Zygote, morula, blastula gastrula, fetus
266.*Draw a sketch of a morula, a blastula, and a gastrula.
Morula
Blastula
Gastrula
267.*Match the tissue types or organs to the embryonic layer from which they develop (ectoderm,
endoderm, mesoderm).
a. Skin develops from…
ectoderm
b. Nervous system develops from…
ectoderm
c. Skeletal system develops from…
mesoderm
d. Kidneys develop from…
mesoderm
Science 9 Final Review Sheet
e. Digestive system lining develops from… endoderm (digestive muscles from mesoderm)
f. lungs develop from…
endoderm
268.*What is the name of the female plant structure that stores egg cells?
The ovule(s) which is located in the ovary
269.*Compare the advantages and disadvantages of internal and external fertilization.
Type of Fertilization
Advantages
Disadvantages
External Fertilization
1. Little energy is needed to
1. More energy is needed to make
find a mate.
large numbers of sperm and egg
2. Large numbers of offspring
cells.
are produced at one time.
2. Many of the reproductive cells
3. Larger numbers of offspring
(gametes – sperm and eggs)
increase the chances of
never form zygotes and die.
survival.
3. Predators feed on many of the
4. Offspring tend to disperse
developing zygotes since they
themselves (spread out) and
are not protected inside a
this reduces competition for
parent’s body.
food.
4. Parents that fertilize externally
5. Dispersed offspring are
do not usually care for their
likely to be fertilized by
offspring so more die for lack of
organisms other than their
care.
parents which increases their
diversity.
Internal Fertilization
1. Less energy is required to
make reproductive cells
since fewer reproductive
cells are needed.
2. Developing embryos are
protected inside the mother
and thus more survive.
3. Mothers protect their
1. Internally fertilizing organisms
require more energy to find a
mate.
2. Some mating behaviours are very
elaborate and require much
energy.
3. Fewer young are born than with
external fertilization.
Science 9 Final Review Sheet
offspring after they are born
so they survive better.
270.How do animals that reproduce using external fertilization increase the chances of an egg cell and a
sperm cell meeting?
They produce large numbers of reproductive cells. (The males produce millions of sperm and the females
produce hundreds to thousands of eggs.) In some species, the males move close to where the females lay
their eggs.
271.A salamander lays eggs in the water and a lizard lays eggs on land. Predict which animal would lay
more eggs at a time, and explain why.
The salamander would lay more eggs since it would fertilize externally in water while the lizard would likely
fertilize internally and would lay eggs or bear its young alive.
272.*How do both the bee and the plant it visits benefit from pollination?
The bee is rewarded with nectar and pollen while the plant gets the male gametes (sperm in pollen) moved to
the female gametes (eggs in ovary of flower)
273.Why would a plant pollinated by a bat not require colourful flowers?
Bats pollinate at dusk or night when there is no light. They can’t see any flowers but detect them through
smells and with their sonar (high-pitched squeaks they bounce off objects to locate them).
274.How do animals transport seeds to different locations?
Science 9 Final Review Sheet
Animals eat fruits with seeds and wherever they defecate, they leave seeds there. Animals also get seeds
caught in their fur/feathers and carry them until they fall off. Some animals (like squirrels) bury seeds in
various spots and forget to retrieve all of them.
275.*What is assisted reproductive technology?
Procedures that help people who are infertile to have children.
276.*What is artificial insemination?
Harvesting sperm and inserting them into the female with an instrument.
277.*What is in vitro fertilization?
Harvesting eggs and sperm and combining them in a laboratory outside of the bodies of the mother and
father.
278.How does the success rate of in vitro fertilization change as the age of the woman increases?
The success rate goes down
279.What is the difference between gamete intrafallopian transfer and in vitro fertilization?
Gamete intrafallopian transfer harvests sperm and eggs and mixes them and then immediately injects them
back into a female’s fallopian tube. In vitro fertilization lets the fertilized eggs develop outside for a while
and then implants the embryos into the uterus.
280.Describe two possible reasons for infertility.
Diseases that damage reproductive organs, poor sperm development, hormone imbalances.
281.*What is the function of the uterus?
The uterus nourishes the developing embryo.
282.*Outline the steps for in vitro fertilization.
A woman is given extra hormones which cause her to release numerous eggs at the same time. The eggs are
harvested as well as sperm from the husband/donor. The eggs and sperm are mixed together, forming a
number of fertilized eggs. The fertilized eggs are allowed to develop into morulas. A number of the morulas
are then implanted into the woman’s uterus.
283.What are some potential side effects of in vitro fertilization for a woman?
The woman may become dizzy, have nausea or headaches.
284.Approximately how many births result from every 100 intracytoplasmic sperm injection procedures?
25% or 25
285.*How can embryos be preserved for an extended period of time?
The embryos are stored in liquid nitrogen
286.*Describe two different types of surrogacy.
A surrogate mother may have an embryo implanted that was formed from another woman’s egg and her
husband’s sperm or another man’s sperm.
A surrogate mother may be asked to supply her own egg that is fertilized with another man’s sperm.
Science 9 Final Review Sheet
287.Consider all the types of reproductive technology described in this chapter. What are some
advantages of reproductive technology?
A woman can pay to have someone else carry her child. Couples normally infertile can now have children.
288.What are some disadvantages of reproductive technologies?
Issues may arise concerning the child’s right to know its biological parents. Children may be born to persons
too old to care for them into adulthood.
289.*Name the three smaller particles that every atom is made up of.
particles are found.
Proton-in nucleus, Neutron-in nucleus, Electron-around the nucleus
State where in the atom these
290.*When is an atom uncharged or neutral?
When the number of protons equals the number of electrons
291.*How are solid materials charged?
By rubbing them against some other material
292.*What is the overall charge when an atom has more protons than electrons?
Positive
293.*What happens to the charge on a neutral atom when:
a. It gains electrons?
It becomes negative
b. When it loses electrons?
It becomes positive
294.*What can happen to electrons during friction or rubbing of one object past another?
Electrons can move from one object into another. They are attracted to the object that has the greatest pull
for them.
295.*In terms of the motion of electrons, what is the difference between an insulator and a conductor?
Insulators will not let their electrons move inside them but conductors will let electrons move inside them.
296.*Explain how an object that is made up of millions of electrons and protons can still be neutral.
As long as the millions of protons have an equal number of millions of electrons, the object will be neutral.
297.What is the purpose of a Van de Graaff generator?
A Van de Graaff generator move electrons from one place to another, causing a large static charge to build
up on a metal sphere.
298.*What are four uses of static electricity?
Static electricity is used in photocopiers, to paint objects, to remove dust particles from air, to stick cling
wrap to bowls.
299.*What is grounding?
Science 9 Final Review Sheet
Grounding is connecting an object to the earth or to a much larger object in order to remove a charge or to
reduce the electrical force in an object.
300.*Why do fuel trucks and airplanes need to be grounded before pumping fuel?
Fuel trucks and planes can get charged and make sparks with objects touching them. Any sparks around
them could cause explosions so they must be grounded to make them neutral and unable to produce sparks.
301.*The word, “static”, in static electricity describes what property of the charge?
This is charge that does not move – it builds up in a given place.
302.When an acetate strip is charged by rubbing, does it acquire a positive or a negative charge?
It becomes positively charged
303.*Draw a diagram of an atom that has three protons, four neutrons, and three electrons.
a. Label the protons, neutrons and electrons.
b. State which particles are neutral, negative or positive
304.*Which particles in an atom are transferred when you charge an object?
Electrons are transferred when you charge an object.
305.*Using + and – signs, make a sketch of
a. A neutral object
+-+-+-+-+-+-+-+
b. A negative object
-+--+--+
+--+--+c. A positive object
+-++-++-++
-++-++-++306.*What is the term for a solid object that holds charges very nearly in one place?
An insulator
307.*What is the term for a solid object that allows free electrons to move easily through it?
A conductor
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308.*What unit is used for measuring static charge?
Coulomb
309.What does it mean to say that a conductor is grounded?
A conductor is attached by means of another conductor to a body much larger than itself, ideally the earth.
310.*What is the purpose of an electroscope?
The electroscope is a device to detect charge.
311.*What are the similarities between a proton and an electron?
A proton and an electron are both charged.
312. *What are the differences between a proton and an electron?
`A proton is about 2000 (1832 x) times heavier. A proton is positively charged while an electron is
negatively charged.
313.*What is the difference between a positively charged object and a negatively charged object?
A positively charged object has more protons than electrons while a negatively charged object has more
electrons than protons.
314.How is it possible for an object to be neutral if it contains millions of electrons?
Being neutral means that the number of positive charges is equal to the number of negative charges.
315.Explain why a person can get a shock by walking across a carpet and then touching a metal object
such as a doorknob.
As a person rubs her/his shoes across a carpet, the person becomes charged because electrons move into or
out of the person. When the charged person touches a neutral doorknob, electrons move to make the person
more neutral and this movement of electrons is the spark.
316.When you touch a charged object with your hand, the object becomes neutral. Explain what has
happened to the charge in this process.
The charge has been removed by electrons moving into or out of the object to the hand.
317.Compare and contrast charged conductors and insulators.
Charged insulators tend to hold their charge because they won’t let it move but charged conductors tend to
lose their charge because they allow free movement of any negative charge through them.
318.*Suppose two identical neutral objects were rubbed together. Is it possible for these objects to gain
a static charge? Explain.
No because they both have an equal attraction for their electrons.
319.*What is the definition of an electric force?
A push or pull between charged objects.
320.*Explain what is meant by action-at-a-distance force.
This is a force that can act on an object without touching the object.
321.*According to the laws of static charge, explain how like charges react.
Like charges repel
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322.*According to the laws of static charge, explain how opposite charges react.
Opposite charges attract
323.*According to the laws of static charge, explain how neutral objects react to positive charges.
Neutral objects attract to positively-charged objects
324.*According to the laws of static charge, explain how neutral objects react to negative charges.
Neutral objects attract to negatively-charged objects
325.*What is electrical force proportional to (directly depending on)?
The electrical force increases with increasing charge on the objects. The electrical force decreases with
increasing distance between the objects.
326.*In terms of charge transfer, what is the difference between charging by conduction and charging by
induction?
Charging by conduction is charging by touching the object with some charged object. The object touched
will get the same charge as the object touching it. Charging by induction is bring a charged object close to
another object followed by grounding the object, removing the ground and then removing the close charged
object. The result is that the object gets a charge opposite to the charge on the charged object that was
brought close to the object.
327.When a charged balloon sticks to the wall, does the wall become charged by induction or
conduction? Explain.
The wall becomes charged by induction as the balloon approaches the wall because the balloon is not
touching the wall then. After the balloon touches the wall it gets charged by conduction.
328.How are contact forces and action-at-a-distance forces different?
Contact forces act by touching an object while action-at-a-distance forces act over a distance without
touching the object.
329.*Describe a situation that involves a contact force.
Pushing a cart
330.*Describe a situation that involves an action-at-a-distance force.
Gravity acting on a ball that is lifted above the ground.
331.*State the three laws of static charge.
Like charges repel, opposite charges attract and neutral objects attract to either positive or negative charges.
332.*A positively charged object is brought near another object. If the two objects repel, what is the
charge on the second object?
The second object has the same charge as the first object.
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333.*A charge is transferred from one conductor to another by touching. What kind of charging process
is this?
Charging by conduction
334.*A charge is relocated within a conductor because there is a charged object nearby. What kind of
charging process is this?
Charging by induction (without touching the object with the charged object).
335.*A positively charged object is brought near a second object. The two objects attract. Does this
observation prove that the second object must be negatively charged? Explain.
The second object could be either neutral or negative.
336.*An unknown material is rubbed with silk and becomes charged. Explain how you could use a
negative acetate strip or a positive glass rod to determine the type of charge on the unknown
material.
Both the negative acetate and the positive glass rod would be brought near the object and whichever object
repelled the unknown material, that would be the charge on the material. (Ex: if the glass rod repelled the
object, the object would be positive like the glass rod.)
337.*Suppose you are handed an electroscope that another student just used. You observe that the leaves
are already spread apart. You now slowly bring a positive glass rod near the knob of the
electroscope and the leaves begin to get closer together. Why did the leaves move closer together
when you brought the glass rod near the knob of the electroscope?
Because the leaves dropped, the charge on the electroscope must have been negative (opposite to the rod’s
charge). The electrons in the leaves of the electroscope would move upward (attracted to the glass rod)
which would leave the leaves neutral and they would fall straight.
338.State the similarities and differences between charging by conduction and charging by induction.
Both methods leave objects charged but with opposite charges. A negative object touching (conduction) an
object makes the object negative. But a negative object brought near to a grounded object and then the
ground is removed, will be positive in charge.
339.*State the relationship of the distance between two charged objects and the force between them.
The greater the distance the less the force between them.
340.*Use your understanding of static charge to explain how plastic wrap clings to a neutral glass bowl.
Plastic cling has a negative charge. When it approaches a glass bowl, it repels electrons to the inside of the
glass bowl so that the outside of the bowl is overall positive which attracts the cling wrap to itself.
341.*A positively charged object is positioned near one end of a neutral metal rod that is supported by an
insulator. If you briefly touch the opposite end of the metal rod with your finger, it becomes
Science 9 Final Review Sheet
negatively charged. Explain how the metal rod became charged without being touched by the
charged object.
The positive object (round) attracted the electrons towards itself. This left the finger end of the rod positive
in charge. When the finger touched the rod, it grounded the rod and allowed electrons to enter or leave the
rod. Since the finger end of the rod is positive, it attracts electrons into the rod, making the rod negative in
charge overall.
342.*What device uses chemical energy to give charges electric potential energy?
A cell or battery.
343.*What is the definition of energy?
Energy is the ability to move things or do work, more specifically to exert a force over a distance.
344.*How is kinetic energy different from potential energy?
Kinetic energy is the energy that moving objects have while potential energy is energy that is stored
345.*What is another name for electric potential difference?
Voltage
346.*What two factors determine the energy the charge possesses? (p272)
The amount of charge there is (number of coulombs) and the voltage that the charge has.
347.*What is the purpose of a voltmeter?
A voltmeter measures voltage.
348.What are two groups of batteries? (p273)
Wet cells and dry cells
349.*How is an electrode different from an electrolyte? (p273)
An electrode is a terminal of a battery while the electrolyte is the moist paste or liquid in a cell that has
positive and negative charged particles (an acid, base or salt).
350.What are five energy sources that can produce electricity? (p274)
Friction, electrochemical cells, piezoelectric crystals, photo cells or solar cells, thermocouples, generators.
351.*What is the amount of energy per unit of charge called? (p272)
Voltage
352.Explain how potential difference in a battery is similar to a staircase. (p272)
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The height of the stairs is like the voltage and the amount of weight lifted up the stairs is like the amount of
charge (coulombs -C).
353.What is another word for potential difference?
Voltage
354.What two factors determine the output energy of a battery? (p272)
The voltage of the battery and the amount of charge the battery has separated.
355.*What device could you use to measure potential difference?
A voltmeter
356.*A battery is a common source of electrical energy. Describe two other methods of producing
electrical energy.
Friction, piezoelectric crystals, photo cells or solar cells, thermocouples, generators.
357.*Explain how an electrochemical cell produces a potential difference across its terminals.
The chemicals in the electrolyte remove electrons from one terminal making it positive and they deposit
electrons at the second terminal making it negative. In the picture below, electrons are being removed from
the Zn electrode (+) and electrons are being deposited at the Cu electrode (-).
358.*A student conducts an experiment of building an electrochemical cell. She places two strips of
silver in a beaker of lemon juice. She then connects a voltmeter to the two strips. Predict what
voltage the voltmeter will measure. Explain your prediction.
She will measure zero voltage because the electrodes are both the same kind of substance.
359.*What other forms of energy can electrical energy be converted into by a load?
Kinetic (motion), heat, light, chemical, sound
360.*What is an electric circuit?
It is a pathway that allows electrons to flow in a continuous ring
361.*Explain how electrons in a circuit are like people on a waterslide.
Electrons are given energy (voltage) by the power source like people walk up a slide (get potential energy).
Electrons in wires are like a person walking horizontally (not losing or gaining energy)
Electrons passing through the load (the device running on electricity) give some or all of their energy to the
load like a person sliding down a waterslide who transforms his potential energy into kinetic energy.
Electrons returning to the power source have zero energy like persons at the bottom of the slide and bottom
of the stairs have no potential energy.
Science 9 Final Review Sheet
362.*What are the four basic components of a circuit?
A source of electrical energy. Conducting wires to give a path for electrons to and from the energy source
and load. The load, a device that uses up the energy of the electrons, converting it to some other form. The
switch, a device to complete the circuit (turned on) or open the circuit (stopping the flow of electricity).
363.What is the purpose of a circuit diagram?
Circuit diagrams give an organized representation of the actual circuit. It is a quick, short-hand way to show
how a circuit works.
364.*From which terminal of a battery are electrons pushed?
Electrons are pushed from the negative terminal
365.When a battery is connected to a circuit, all the electrons throughout the circuit immediately start to
move. How is this possible considering that most of the electrons in the circuit are far from the
battery?
Each electron is negative, all the same charge. If one is pushed by a negative voltage, it transmits a force
across a distance to the next electron which transmits its force over a distance to the next etc. Thus the force
exerted at one end is transmitted across a distance from one to the next causing almost instantaneous
movement throughout.
366.Why is the charge in a battery not an example of static electricity?
The charge in a battery is continuously made or built up through chemical reactions and can cause a steady
flow of electrons from one place to another.
367.*Define electric current.
Electric current is the amount of charges (coulombs of electrons) flowing past a point per second.
368.*What are the units of electric current?
Amperes or amps (A)
369.*What is the purpose of an ammeter?
An ammeter measures electrical current, the amount of electron flow.
370.*How is electron flow different from conventional current?
Electron flow is a flow of electrons from negative to positive. Conventional current is an imaginary flow of
positive charges from positive to negative.
371.*What is the function of the battery in an electric circuit?
A battery provides the energy (voltage or “push/pressure”) to move electrons.
372.*What are three different examples of loads?
A light, a motor, a heating element
373.*Draw and label each of the following circuit symbols:
a. Conducting wire
Science 9 Final Review Sheet
b. Cell
c. Battery
d. Light bulb
e. Open switch
f. Closed switch
g. Voltmeter
h. Ammeter
374.*What is the amount of charge passing a given point every second called?
The amperes of electrical current
375.*State the correct units of electric current.
Amperes (A)
376.*What device is used to measure electric current?
Ammeter
377.What is the difference between electron flow and conventional current?
Electron flow is a flow of electrons from negative to positive. Conventional current is an imaginary flow of
positive charges from positive to negative.
378.*Explain the difference between static electricity and current electricity.
Static electricity is a charge build-up in a place that is not moving. Current electricity is electrons moving
through a conductor.
379.*A circuit contains a 3.0 V battery and a light bulb. Suppose the battery were replaced by a 6.0 V
battery. Would the electrical energy transformed in the light bulb increase or decrease? Use the
example of a waterslide to explain your answer.
The energy would increase, the bulb would glow brighter. This is like a water slide that is twice as high so a
person sliding down it would move faster and get more energy because of the extra height.
380.Explain how electrons are “pushed” through a conductor without having to touch other electrons.
Science 9 Final Review Sheet
Since electrons repel each other, if they get “pushed” to move at one end of a conductor, that push is
tranmitted throughout the entire conductor because it acts over a distance from one electron to the next to the
next throughout the conductor.
381.Explain how two conductors could have different current even though the electrons in each
conductor are travelling at the same speed.
Current is the number of electrons going by (how many) per second, not how fast the electrons are moving.
So in two conductors, the electrons will be moving at the same speed but in one there may be twice as many
moving which is twice the amps (amperes).
382.Draw a circuit diagram for the circuit shown.
Remember that R = V/I, and the pyramid above
problems.
383.*How does resistance affect current?
More resistance slows or lowers current flow.
to solve the following
384.*What will happen to the current in a circuit if the voltage applied to that circuit is increased?
The current will increase if the energy (voltage) or “pressure” behind it increases.
385.*State Ohm’s Law, which is the relationship of voltage (V), current (I), and resistance (R) .
R = V/I
386.*What are the units of electrical resistance?
Ohms (Ω)
387.*What happens to the electrical energy when electrons flow through a resistor?
The electrical energy is changed into other forms of energy and ultimately into heat.
388.*What does it mean when we say that energy is “lost” in a resistor?
The resistor uses up the energy of the electron flow and converts this to heat or some other form of energy.
389.How do manufacturers of resistors indicate the value of the resistance?
They put different colour rings around the resistor.
Science 9 Final Review Sheet
390.*What is the name of the property of a material that slows down current and converts electrical
energy into other forms of energy?
Its electrical resistance.
391.*The current through a load in a circuit is 1.5 A. If the potential difference across the load is 12 V,
what is the resistance of the load?
8Ω
R = V/I R = 12 V/1.5 A
392.*The resistance of a car headlight is 15 Ω. If there is a current of .80 A through the headlight, what
is the voltage across the headlight?
12 V V = R x I, V = 15 Ω x .8 A
393.*A 60 V potential difference is measured across a load that has a resistance of 15 Ω. What is the
current through this load?
4 A I = V/R, I = 60 V/15 Ω
394.*A 15 mA current flows through a 400 Ω lamp. What is the voltage across the lamp?
V = R x I .015 A = I 400 Ω = R V = 400 Ω x .015 A = 6 V
395.*A 12 kΩ load is connected to a 90 V power supply. What is the current through the load in
milliamperes (mA)?
I = V/R V = 90 V, R = 12 000 Ω ; I = 90 V/12 000 Ω = .0075 A = 7.5 mA
396.*A device draws a current of 1.2 mA when connected to 120 V. What is the resistance of this device
in ohms and also in kilo-ohms.
R = V/I V = 120 V, I = 1.2 mA = .0012 A; R = 120 V/ .0012 A = 100 000 Ω = 100 K Ω
397.*Using Ohm’s Law, state the relationship of current, resistance and voltage.
R = V/I As the voltage on a resistor is increased, the current through the resistor will increase in direct
proportion to the voltage.
398.*What two values do you need in order to calculate resistance?
Voltage and current
399.What is the unit of resistance and what is its symbol?
Ohm and Ω
400.*What is used to control current and potential difference in a circuit?
resistors
401.Explain how manufacturers indicate the value of resistance on each resistor.
Manufacturers use coloured rings to indicate the resistance value.
402.*Draw the symbol used to represent a resistor in a circuit diagram.
Science 9 Final Review Sheet
403.*A 1.2 A current flows through a 250 Ω resistor. Calculate the voltage across this resistor.
V=RxI
R = 250 Ω, I = 1.2 A
V = 250 Ω x 1.2 A = 300 V
404.*A 120 Ω resistor is connected to a 12 V battery. Calculate the current through the resistor.
I = V/R
V = 12 V, R = 120 Ω ;
I = 12 V/120 Ω = .1 A = 100 mA
405.*An unknown resistor transforms 2.0 mA of current when connected to a 9.0 V battery. Calculate
the resistance value of this resistor.
R = V/I
V = 9.0 V, I = 2.0 mA = .0020 A; R = 9.0 V/.002 A = 4500 Ω = 4.5 k Ω
406.A classmate hands you a resistor that has the following colour bands: yellow, orange, red and silver.
What is the resistance of this resistor?
43 x 102 Ω = 4300 Ω = 4.3 k Ω
407.*A light bulb is connected to a battery and the brightness of the light is observed. A resistor is then
connected between the battery and the light bulb and the brightness of the light decreases. Explain
this observation using what you know about energy and circuit components.
The resistor is using up some of the energy (voltage) of the electric current so that the light bulb no longer
has the full energy it did before.
408.*Draw a circuit diagram for the following circuit and add an ammeter, connected properly, anywhere
in the diagram.
409.*What do we call a circuit that has only one path?
A series circuit
410.*What happens to the current in a series circuit when a switch is opened?
The current stops everywhere in the circuit
411.*How does the total voltage lost on all loads compare to the total voltage supplied by the battery?
The voltage lost on all loads is equal to the voltage supplied by the battery
412.*Why is the current at any two locations in a series circuit always the same?
Science 9 Final Review Sheet
Since there is only 1 path, current (electron flow) can only be of one value. If current were to speed up in
one place, this would be instantly transmitted throughout all the electrons which would all flow at the new
rate.
413.*If a resistor is added in series to an existing resistor, what happens to the total resistance?
The total resistance goes up and would be equal to the sum of the resistor’s resistances.
414.*What is the name given to a circuit that contains more than one pathway?
A parallel circuit.
415.*Two loads are connected in parallel. Compare the voltage across each load.
The voltages of each load would be identical to each other.
416.*Two loads are connected in parallel. Must the current through one load equal the current through
the other load?
No. The current can be different in each of the parallel branches.
417.*What name is given to a location in a circuit where the circuit branches into more pathways or
where pathways rejoin?
A junction point
418.*How does current entering a junction point compare to current leaving that same junction point?
The current entering the junction point will be equal to the current leaving the junction point.
419.*If you add a resistor in parallel to an existing resistor, what happens to the total resistance in the
circuit?
The total resistance becomes less.
420.*How is a parallel circuit different from a series circuit?
A parallel circuit has two or more paths while a series circuit has just one path.
421.*In a series circuit, how does the voltage supplied by the battery compare to the voltages on each
load?
In a series circuit, the voltage supplied is equal to the sum of the voltage losses of all the loads. In a parallel
circuit the voltage supplied is equal to the voltage loss of each load.
422.*What happens to the total resistance of a series circuit when another resistor is added in series?
The total resistance becomes greater with each resistor added in series (It is the sum of all the loads’
resistances).
423.*What happens to the total resistance of a parallel circuit when another resistor is added in parallel?
In parallel circuits, the total resistance lessens with each resistor added in parallel.
424.*Two resistors are connected in parallel to a battery. In comparison, what must be the voltage across
each of these two resistors?
In parallel, the voltage loss of each of the resistors is the same as the voltage supplied.
425.*Is the current in one branch of a parallel circuit more than, less than, or equal to the total current
entering the junction point of the circuit?
Science 9 Final Review Sheet
The current in one parallel branch is always less than the total current entering the junction point.
426.*The battery in the following circuit is 9.0 V. In this circuit, find :
a. The current through resistor 2
The current through resistor 2 is 2.0 A
b. The voltage across resistor 2
The voltage across resistor 2 is 6.0 V because 3 V (voltage drop) + 6 V (voltage drop) = 9 V (the voltage
rise)
427.*For the following circuit, find:
a. The current through resistor 2
The current through resistor 2 is 2.0 A because 1A + 2 A = 3 A (The total outside current)
b. The voltage across resistor 2
The voltage across resistor 2 is 9.0 V because in parallel the voltage supplied by the power source is equal to
the voltage loss in each parallel branch.
428.*You are given the following circuit. A second resistor is now added in series with resistor 1.
Science 9 Final Review Sheet
a. Draw the new circuit diagram.
b. Comparing your new circuit to the original, describe the changes in
i. Total resistance
The total resistance is greater than before.
ii. Current leaving the cell
The current leaving the cell would be less.
iii. Voltage across resistor 1
The voltage across resistor 1 would be less since the new resistor in series is using up
some of the voltage. (The sum of the voltages of the loads now would be equal to the
voltage used by the resistor before adding the new resistor in series.)
429.*You are given the following circuit. A second resistor is now added in parallel with resistor 1.
a. Draw the new circuit diagram.
b. Comparing your new circuit to the original, describe the changes in
i. Total resistance
The total resistance would be less now.
ii. Current leaving the cell
The current leaving the cell now would be more because the total resistance is less.
iii. Voltage across resistor 1
Science 9 Final Review Sheet
The voltage across resistor 1 would be the same as before since every parallel branch
has the same voltage loss.
430.*A flashlight bulb operates on 3.0 V and draws a current of 4.0 A. What is the power of this bulb?
P = V x I = 3.0 V x 4.0 A = 12 W
431.*A 60 W light bulb is connected to 120 V. What current passes through the light bulb?
I = P/V = 60 W/120 V = 0.5 A
432.*A voltmeter measures 15 V across a 45 W resistor. What current is passing through the resistor?
I = P/V = 45W/15 V = 3 A
433.*How much electrical energy is consumed by a 60 W light bulb if it is left on for 25 minutes?
60 W = .060 kW
25 min = 25/60 h = .41667 h
E = P x t = .060 kW x .41667 = .025 kWh
434. *A 1600 W kettle is turned on for 3.0 min. How much electrical energy does the kettle use in this
time?
1600 W = 1.6 kW
3.0 min = 3/60 h = .05 h
E = P x t = 1.6 kW x .05 h = .08 kWh
435.*How much electrical energy is consumed by a 100 W light bulb left on for 4.0 h?
100 W = .1 kW
E = P x t = .1 kW x 4.0 h = .4 kWh
436.*Define power
Power is the rate of using energy, E/t
437.*How are power (P), voltage (V), and current (I) related?
P=VxI
438.*What does the power rating of 40 W mean in terms of energy and time?
40 W means that a device is using 40 J/s or it is using up 40 J of energy per second of time.
439.*What is the formula that relates the energy consumption (E) to power (P) and time (t)?
E = Pxt
440.*What unit of energy is commonly used when dealing with large quantities of energy?
Kilowatt-hour or Megajoule (MJ)
*Use the following table to answer questions 12-13 below.
Appliance
Power (W)
Time of Use
Energy
Each Day (h)
Consumed
(kWh)
Television
200
2.0
.4
Cost in Cents
(cents) at 7¢
per kilowatthour
2.8
Cost in Dollars
(dollars)
.028
Science 9 Final Review Sheet
Stereo
80
1.5
.12
.84
.0084
Kitchen stove
12 000
2.0
24
168
1.68
Microwave
1 400
.5
.7
4.9
.049
100
4.0
.4
2.8
.028
Bedroom light
441.*In the above table calculate the energy consumed by each appliance in kilowatt-hours. Be sure to
change your watts into kilowatts.
442.*In the table above calculate the cost (in cents and dollars) of the electrical energy used in terms of a
cost of 7 cents per kilowatt-hour.
443.*Which appliance had the greatest cost per day? In your home, which appliance would likely have
the greatest cost per day?
The kitchen stove
*Complete the following table for questions 15-17 below.
Resistance (Ω)
Voltage (V)
Current (A)
100
1.5 V
.015
Power (W)
.0225
500
1.5 V
.003
.0045
1000
1.5 V
.0015
.00225
444.*Use Ohm’s Law to determine the current each resistor will draw.
445.*Use P = VI to determine the power that each resistor uses.
446.*Based on the table above, would a 60 W or a 100 W light bulb have more resistance?
The 60 W bulb would have a lower current flow and higher resistance
447.*What do we call the rate at which energy is transformed?
power
448.*State one unit for energy and one unit for power.
Energy – J
Power - W
A
449.*What is another name for joules per second?
J/s is a W (watt)
450.*In which unit are large amounts of energy measured?
kWh
451.*How many joules is 1 kWh equal to?
1 kW = 1000 W and 1 h = 3600 s ( 60 min x 60 s = 3600 s)
1 kWh is
1000 W x 3600 s = 3 600 000 J/s x s/1 = 3 600 000 J
Science 9 Final Review Sheet
452.*State the relationship of energy (E), power (P), and time (t)
E=Pxt
453.Two identical batteries are connected to different circuits. Explain how it is possible for the batteries
to supply different amounts of power.
Power, P = V x I. The volts supplied to both circuits will be the same because the batteries are identical but
the current in each circuit may be quite different. The circuit which uses the most current will use the most
power (Psmaller = V x Ismaller , Plarger = V x Ilarger)
454.*Explain how two loads can consume the same amount of electrical energy but have different power
ratings.
Since E = P x t , A larger power consumption for a smaller time can use the same energy as a smaller power
consumption uses for a larger amount of time.
455.*What is the power rating of a light bulb if 3.0 A flow through it when connected to a 15 V battery?
P=VxI
= 15 V x 3.0 A = 45 W
456.*How much electrical energy, in joules, does a 40 W light bulb consume in 15 min?
40 W = 40 J/s
15 min = 15 min x 60 s/min = 900 s
E = P x t = 40 J/s x 900 s = 36 000 J
457.*A 1600 W hair dryer is used for 15 min. How much electrical energy, in kWh, did the hair dryer
consume during this time?
1600 W = 1.6 kW
15 min = 15 min/60min/h = .25 h (1/4 h)
E = P x t = 1.6 kW x .25 h = 0.4 kWh
458.*If the cost of electricity is 7 cents/kWh, how much does it cost to use the hair dryer in number 28
above?
0.4 kWh x 7¢/kWh = 2.80 ¢
459.*In a set amount of time a battery supplies 25 J of energy to an electric circuit that includes two
different loads. One of the loads produces 10 J of heat energy during this time interval. How much
heat energy is produced by the second load in this time? Explain your answer.
The second load produces 15 J of energy. The amount of energy used must equal the amount of energy
delivered. Energy is conserved.
460.*What did Edwin Hubble notice about the direction of movement of galaxies in space?
Galaxies appeared to be moving away from each other with the farthest ones from us moving at the fastest
speeds. Also, if the path of each galaxy’s motion were traced back to where it had been before, the paths of
the all the galaxys came to a single point in space.
461.*What conclusion did Hubble make when he observed that distant galaxies appeared to be moving
away from each other?
He concluded that they were together in some way at some earlier time and a massive explosion drove them
apart.
462.*Name four types of electromagnetic radiation.
Visible light, microwaves, radio waves and X rays
Science 9 Final Review Sheet
463.*What is a spectrum?
A spectrum is the pattern of colours coming from an object giving off electromagnetic radiation (some form
of light).
464.*What is indicated by a shift of a galaxy’s spectral lines toward the red part of its spectrum?
The galaxy is moving away
465.*What did Edwin Hubble discover about the spectra of the galaxies he observed?
Hubble noticed that spectral lines were all shifted towards the red end of the spectrum.
466.*What do we call radiation that is carried in the form of waves?
Electromagnetic radiation
467.*What is the purpose of a spectroscope?
A spectroscope makes light spread out into a spectrum. It separates the various waves travelling together.
468.*What does the cosmological red shift suggest about the motion of galaxies?
The galaxies are expanding outward from a point. The universe is expanding.
469.*State the main idea of the Big Bang theory.
All matter was very concentrated at one time in a fairly small region of space. It suddenly expanded to a
very large size and pushed everything out from the centre. As the matter moved outward, it formed atoms
and these eventually made galaxies, stars and planets.
470.*Give one piece of evidence that supports the Big Bang theory.
All sky objects appear to be moving outward (their light red-shifted) with the farthest moving the fastest.
471.*According to the Big Bang theory, how did the temperature of the universe change as the universe
expanded?
At first the temperature was extreme but as the expansion continued, matter cooled so that at the outermost
edges of the universe matter is only a few degrees above absolute zero, the lowest temperature possible.
472.What evidence did Edwin Hubble use to suggest the universe was expanding?
The fact that the most distant sky objects from us have the greatest red-shifts of their spectral lines while
closer sky objects show smaller red-shifts is consistent with an expanding universe.
Science 9 Final Review Sheet
473.How is a loaf of raisin bread baking in the oven a simple model of Hubble’s view of an expanding
universe?
As the loaf expands as it is baked, raisins closer to a given raisin seem to move away less far than do raisins
farther away from the given raisin which seem to move farther away.
474.Both the COBE satellite and WMAP were designed to measure temperatures only a few degrees
above absolute zero. Why was it necessary to take these measurements in space rather than than
from Earth?
The heat on Earth and in its atmosphere would interfere with the sensitive satellite instruments and make the
temperature readings of distant space objects appear to be much higher than they really are.
475.How does the pattern shown in the WMAP map indicate that the presence of microwave radiation in
the universe is not the same everywhere?
The blue regions are denser regions of early space where galaxies are thought to have formed. Red areas are
less dense regions that have becomed emptier and emptier as time has progressed.
476.*How does cosmic background radiation provide evidence for the Big Bang theory of the origin of
the universe?
If there was some kind of explosion that started our universe then one would expect the remains of this to be
pushed out on the very edge of our expanding universe. As it cooled, it would be a faint afterglow of an
original fantastic blast. We find everywhere at the edges of our universe in all directions a faint glow, a
“noise-like” (unorganized) radiation of microwaves. This faint light energy is called the cosmic background
radiation because it is found throughout our cosmos (universe) at its farthest edges.
477.Why is cosmic background radiation important in the study of the formation of galaxies?
This kind of radiation would indicate the formation of atoms and eventually galaxies if the radiation were
somewhat uneven rather than totally even. The WMAP probe has taken photos of the microwave radiation
at our universe’s edges that indicate the kind of unevenness needed to form galaxies.
478.*What is a nebula?
A nebula is a cloud of gas and dust in space
479.What is the difference between a nebula and a galaxy?
A galaxy is an enormous collection of gas, dust and billions of stars held together by gravity.
Science 9 Final Review Sheet
480.*List the three basic shapes of galaxies.
Spiral, Elliptical (like a football or cigar), Irregular
481.*What characteristics do all galaxies share?
The have millions of stars, dust and gas – all held together by strong gravity forces
482.What do we call stars that are bunched together in part of a galaxy?
A star cluster
483.*Even if humans had a spaceship that could travel at the speed of light, it is unlikely they would ever
travel across our galaxy. Explain.
It would take 100 000 years for a person to travel across just the stellar disk of the Milky Way galaxy,
travelling at the speed of light. Most persons only live to 70-90 years.
484.Not every star visible from Earth has a name. Why not?
It is much easier to number the stars than to name each one since there are million/billions to name.
485.Earth is located in one of the arms of the spiral galaxy, the Milky Way. How do you think the
appearance of the night sky would differ if our location were much closer to the centre of the galaxy?
The night sky would be much brighter, perhaps even brighter than our daytime sky is now.
486.How does the speed at which a galaxy rotates affect its shape?
The faster the galaxy rotates, the flatter it becomes.
487.*Besides shape, what other ways do galaxies differ from each other?
Galaxies differ in size, in mass, in colour, in brightness, in speed of spin, in the number of stars they contain,
in the type of stars they contain, and the kind of gas and dust they contain.
488.Does the statement “Galaxies would not exist if it were not for nebulas” make sense? Explain.
This makes sense because galaxies form from nebulas (clouds of gas and dust that gather together because of
gravity to form stars).
489.*What nuclear process combines two atomic nuclei to form one heavier element?
Atomic fusion
490.*What are the three basic classifications of stars?
Low mass, Intermediate mass and high mass stars
491.*How is our star, the Sun (Sol), classified?
The sun (Sol) is an intermediate star
492.*What is the explosion of a very large star called?
Supernova
493.*Why do astronomers call a black hole “black”?
A black hole has such strong gravity that it pulls back the light it makes back into itself.
494.*What two star characteristics does the Hertzsprung-Russell diagram compare?
Science 9 Final Review Sheet
A star’s luminosity is compared to its temperature/colour.
495.What is a star’s spectrum?
The various forms of light radiation that the star gives off, the light wavelengths a star gives off.
496.*What two things can the colour of a star tell astronomers?
The colour of a star indicates the temperature it is at, as well as what it is composed of.
497.*Describe the Doppler effect.
The Doppler effect is for an object that is moving and giving off waves. The moving object will have these
waves compressed to smaller lengths in front of it while behind it, the waves will be stretched out into longer
wavelengths.
498.*If astronomers observe a star’s spectrum shifted toward the red end, how is the star moving relative
to Earth?
The star is moving away from the Earth.
499.*What makes up most of interstellar matter?
Hydrogen and dust
500.*Briefly explain how a star forms.
Gravity pulls a nebula cloud together and this heats the cloud up. Eventually, as the cloud shrinks into a
dense ball, the temperature reaches 30 000 000 degrees Celsius which causes atomic fusion to start. The
cloud begins to shine – a star is born!
501.*Is our Sun a low mass, intermediate mass or high mass star?
Our star is an intermediate mass star.
502.*Describe a supernova.
A large mass star (12-15 times the mass of our sun) reaches the stage where its internal fusion processes
make iron or nickel. This causes instability in the star and it implodes (contracts inward) and then has a
massive explosion outwards
503.*How does a black hole form?
Stars more than 25 times our sun’s mass will explode in a supernova and then collapse into themselves. All
the space between and inside atoms collapses into just a ball of matter with so much gravity that it pulls back
the light it makes into itself.
504.What is a star’s spectrum?
The various wavelengths of light (different kinds of radiation) that a star sends out.
505.*Explain the Doppler effect.
A moving object giving off waves has those waves compressed to smaller lengths in front of it while behind
it, its waves will be stretched out into longer wavelengths.
506.*Describe the process of fusion in a star.
Fusion is when two light atoms have their nuclei fused into a larger nucleus, making a new heavier element.
This process only happens at temperatures exceeding 30 000 000 degrees Celsius.
Science 9 Final Review Sheet
507.*What else is produced from a fusion reaction?
A fusion reaction produces a new heavier element, extra neutrons and an extremely large amount of energy.
508.*Why do black holes have such extraordinary gravitational pull?
They have incredibly huge masses in a very small volume which produces extreme gravity force.
509.What will eventually happen to all the stars in the universe?
All stars in the universe will eventually burn out, cool off and become cold, dark matter.
510.*Place the following in order from youngest to oldest
a. a star b. nebula
c. red giant
d. white dwarf
nebula, star, red giant, white dwarf
511.*Using the Hertzsprung-Russell diagram for guidance, describe the temperature-luminosity
relationship for each of the following types of stars.
a. White dwarfs
White dwarfs are hot and dim
b. Red giants
Red giants are cool and very bright
c. Supergiants
Super giants are a moderate temperature and very bright
512.Why is it more difficult to describe the position of a main sequence star than the ones above on the
Hertzsprung-Russell diagram?
Main sequence stars can range anywhere from bright and hot to dim and cool.
513.*How is the colour of a star related to its temperature?
Cooler stars are red and as they get hotter they go to yellow and still hotter they become blue and the very
hottest are white.
514.How long ago do most scientists think that the Sun and planets formed?
The sun and planets are thought to have been formed 5 billion years ago.
515.*What are the two main materials that make up the Sun?
The main components of the Sun are hydrogen and then helium.
516.*What is the name for the dark areas on the photosphere of the Sun?
The dark areas on the photosphere of the Sun are sunspots.
517.*Define solar wind.
Solar wind is a flow of high energy particles from the Sun.
518.*What are the names of the light phenomena that occur in the sky at the North and South poles?
The Northern Lights or Aurora Borealis is the light phenomenon at the North pole. The Southern Lights
or Aurora Australis is the light phenomenon at the North pole.
519.*Explain why the light phenomena at the Poles occur.
Science 9 Final Review Sheet
Solar wind particles are trapped by the Earth’s magnetic field. As they collide with Earth’s atmosphere
atoms, they push electrons to higher levels and when these electrons drop to lower levels, they emit light
of various colours depending on how many levels they fall.
520.*What are the two groups into which we divide planets?
The planets are grouped into the terrestrial and gas giant planets.
521.Name two planets that do not have moons.
Mercury and Venus have no moons.
522.*Where is the asteroid belt?
The asteroid belt is found between Mars and Jupiter.
523.*How many planets in the solar system have liquid water, ice and water vapour clouds?
Earth is the only planet that has water in the form of ice, liquid water and water vapour (gas).
524.*Describe the objects that are found in both the Kuiper Belt and the Oort Cloud.
The Kuiper Belt contains dwarf planets and other small rocky bodies about the size of Pluto and the Oort
Cloud contains smaller icy and rocky fragments.
525.Why is most of the mass of the solar system contained in the Sun?
When our Solar System formed, the centre of the nebula cloud contained more mass which made it have
a stronger gravity pull and this gravity pull brought most of the hydrogen material in the solar system to
the centre making it the most massive part of the solar system.
526.*Briefly describe the protoplanet theory of planet formation.
As a cloud of gas and debris circles, debris collides and clumps due to gravity into larger and larger
bodies which gain more gravity and collect more material to them until all the material is used up or a
nearby star ignites and its solar wind pushes away the remaining material.
527.What name is given to a group of planets that orbit a star?
Planets orbiting the sun are called a solar system.
528.Why do sunspots appear as dark areas on the Sun’s surface?
Sunspots are regions on the Sun’s surface that are cooler so they look darker against the hotter and
brighter parts of the Sun.
529.What is solar wind?
Solar wind is a flow of energetic, charged particles ejected from the Sun.
530.*Describe two differences between the inner and outer planets.
The inner planets are smaller and more dense, composed of rocky materials while the outer planets are
much larger, less dense composed of lighter gases.
531.Name a planet that has no atmosphere.
Mercury has no atmosphere
532.*Where is the Kuiper Belt found?
The Kuiper Belt is found as a ring of larger asteroid-like bodies beyond the orbit of Neptune.
Science 9 Final Review Sheet
533.*Describe the composition of a comet.
Comets are composed of mostly ices with some rocky materials.
534.Describe the materials that both the Kuiper Belt and the Oort Cloud contain.
The Kuiper Belt contains mostly dwarf, rocky planets while the Oort Cloud is composed mostly of ices,
smaller rocky fragments and comets. The Oort Cloud is thought to be the source of comets.
535.An astronomical unit (AU) is the average distance between Earth and the Sun. Explain why the
distances between bodies in the solar system are measured using AUs.
Measuring in km would give numbers far too large and measuring in light-years would give ridiculously
small numbers. Bu using Aus, we show how far other planets are from the sun in terms of our own distance
which produces numbers that are neither too large nor too small and also give a direct comparison to our own
distance from the sun.
536.Compare and contrast a planet with a solar system.
A planet is just a body orbiting a star and the orbiting planets and starts make up a solar system.
537.*Compare and contrast rotation with revolution.
A planet’s rotation is its spin on its own axis while its revolution is its orbit around a star.
538.*Compare and contrast comets with asteroids.
Comets are bodies that orbit the sun which are composed of ices and rock debris ans which come from the
Oort cloud. An asteroid is a rocky body that comes from the asteroid belt and that is captured by the gravity
of a planet and either burns up in the planet’s atmosphere or crashes into the surface of the planet creating a
crater.
539.Is it possible for an object in space to revolve but not to rotate? Explain.
No because even if a planet were not turning on its axis, as it made one complete revolution around a star, it
would also have made one rotation.
540.*Describe the shape of the paths of planets that orbit the Sun.
The planets travel around the Sun in oval orbits called ellipses.
541.Although asteroids orbit as planets do, why are asteroids not considered to be planets?
Asteroids are generally much smaller than planets and form a belt rather than a single body orbiting the Sun.
542.Explain why the frozen debris found in the Oort cloud, more than 50 000 AU away from the Sun, is
still considered part of the solar system.
The Oort Cloud is the source of comets that periodically orbit through our Solar System around the Sun.
543.*The photographs that follow show parts of the most recognizable features of three planets in our
solar system. Name the planets and the features.
Science 9 Final Review Sheet
(a) is Jupiter
(b) is Saturn
(c) is Mars (note ice cap)
544.*What are the large circular features on the Moon called?
Craters
545.*How did these large circular features form?
Meterites crashed into the surface of the Moon
546.*The surface of the Moon has areas of light and dark patterns. Name them.
The dark patterns are called mares. The lighter areas are called lunar highlands, th oldest parts of the Moon’s
surface.
547.*What are lunar phases?
Lunar phases are the changing appearance of the Moon as it orbits Earth due to the lighting of the Sun.
548.*Why do lunar phases occur?
Lunar phases occur because the Moon is lit partially, full or not at all by the Sun as its orbits Earth.
549.How long does it take the Moon to make a complete revolution around Earth?
The Moon takes 29.5 days to revolve completely around the Earth.
Science 9 Final Review Sheet
550.*What is an eclipse?
An eclipse is the total or partial overshadowing of one celestial body by another.
551.*What blocks the Sun’s light during a lunar eclipse?
During a lunar eclipse, the Earth blocks sunlight from falling on the Moon.
552.*What is the darkest part of the Moon’s shadow on Earth called?
The darkest part of the Moon’s shadow is called the umbra.
553.*Why do you see only a partial eclipse if you are standing in the penumbra?
The penumbra is only a partial shadow so only part of the Sun’s light is blocked by the moon.
554.Why does a solar eclipse not occur every time the Moon passes between the Sun and Earth?
The moon orbits Earth in a different plane than the Earth revolves about the Sun. Only every so often does
the Moon come between the Earth and Sun.
Science 9 Final Review Sheet
555.*What does heliocentric mean when used to describe the heliocentric model of the solar system?
Heliocentric means sun-centred. It is the solar system model accepted today.
556.*Compare and contrast the terms, mare and highlands.
The mares are the dark regions of the Moon, made up of flows of basalt, while the highlands are the lighter
and older surface parts of the Moon.
557.*Compare and contrast the terms, solar eclipse and lunar eclipse.
A solar eclipse is when the Moon comes between the Sun and Earth, casting a shadow on the earth. A lunar
eclipse is when the Earth comes between the Sun and Moon and casts a shadow on the Moon.
Science 9 Final Review Sheet
558.Use the diagram on page 425 (diagram for question 3) to answer the question 16-20 below.
559.*State at which Moon location Earth would experience a new moon phase.
At position B the Moon would be at a new moon phase.
560.*State at which Moon location Earth would experience a full moon phase.
At position D the earth would experience a full moon phase.
561.*State at which Moon location Earth would experience a solar eclipse.
Science 9 Final Review Sheet
At position B the Earth would have a solar eclipse
562.*State at which Moon location Earth would experience a lunar eclipse.
At position D there would be a lunar eclipse
563.Why would there never be a lunar eclipse during a new moon phase?
Because the moon is between the Sun and earth during a new moon phase which is a solar eclipse position
not a lunar eclipse position.
564.*Why is there night and day on Earth?
Because the Earth rotates bringing parts of itself into light and plunging other parts into darkness.
565.*Explain the reason why Earth experiences high and low tides.
The Moon revolves around the Earth and as it does, its gravity pulls the water higher on the Earth side facing
and away from it.
566.*Define the word, “constellation”.
A constellation is a group of stars that forms a distinctive pattern.
567.*What name is given to the pieces of rock that burn up passing through the atmosphere?
Meteor or a shooting star.
Science 9 Final Review Sheet
568.*In the diagram of Aristotle’s model of the solar system (Page 425, question 9), there are three
errors. Describe these three errors.
1. The earth is in the centre of the solar system.
2. The earth is surrounded totally by water (not totally), by air (OK), fire (no way).
3. The sun is orbiting the earth.
4. The stars were thought to all be attached to an outer sphere – totally absurd.