Download 1 - Kawameeh Middle School

Name: ___________________________________
Midterm Proficiency Study Guide
7th Grade Science – Miss Maxwell & Mr. Burgmeyer
Exam Dates: Wed. 1/28 and Thurs 1/29 Period: _________
1. What is an atom? List and describe the three parts of an atom.
The smallest particle/the building block of matter. The three
particles inside an atom are the proton (positive charge, found in
the nucleus), the neutron (neutral charge, found in the nucleus), and
the electron (negative charge, found outside the nucleus in the
electron cloud)
2. What makes an atom of one element different from an atom of
another element?
Each atom has a specific number of protons in its nucleus, atoms of
different elements have different atomic numbers and therefore
different numbers of protons.
3. What is a physical property? Give 2 examples.
A characteristic of matter that can be observed or measured without
changing the matter. Density and mass.
4. What is a physical change? Give 2 examples.
A physical change, changes the appearance of matter, but NOT the
identity of the matter. Changes in state, crushing ice
5. What physical property of matter can be used to identify unknown
substances?
Density can be used to identify unknown matter, as all materials
have a unique density, and density is size-independent which means
it will not change with the size of a sample.
6. What is a chemical property? Give 2 examples.
Chemical properties are properties of matter that can only be
observed as matter undergoes a chemical change. Ability to burn,
ability to rust.
7. What is a chemical change? Give 2 examples.
A change in matter in which new substances are formed, and the
identity of the matter changes. Burning, rusting
8. What is a chemical equation? How do you write one? What are
reactants and products?
A chemical equation shows all the chemical formulas involved in a
chemical reaction. To write a chemical equation, you must make
sure that the number of atoms of each element are balanced on both
sides. Reactants are the substances that undergo the chemical
change, products are the substances both old and new formed after
a chemical reaction has occurred.
9. What is the law of mass conservation? How does this relate to the
masses of the reactants and products of a reaction?
The law of conservation of mass states that mass before and after a
change is the same. The mass of the products in a chemical
equation must be equal to the mass of the reactants.
10. What is potential energy? Give 2 examples.
Energy stored inside an object, due to position. A clock on the wall,
a book on a shelf
11. What is kinetic energy? Give 2 examples.
Energy an object has due to its motion. A skier riding down a hill, a
car driving on the road.
Type of Energy
Definition
Example
Energy stored in and
chemical
released in the bonds
Food
between atoms.
Energy stored in and
nuclear
released from the
nucleus of an atom
Nuclear power plant,
the Sun
electrical
sound
Energy that flows in
an electric current
Electrical outlet
Energy that travels
Singing
in sound waves
Energy that travels
radiant
in electromagnetic
microwaves
waves
The sum of kinetic
thermal
and potential energy
Heating or cooling
in the particles of an
particles in an object
atom
The sum of kinetic
mechanical
and potential energy
within a system
A football thrown
through the air
12. Compare the movement and energy of the particles at a cold
temperature and a warm temperature.
Particles at a cold temperature move slowly and are packed close
together, particles at a warmer temperature spread out and move
faster.
13. What is an energy transfer? Give an example.
When energy moves from one object to another without changing
form. A tennis player uses mechanical energy to swing a tennis
racket and transfers that mechanical energy to the ball when the
racket makes contact.
14. What is an energy transformation? Give an example.
When energy changes from one form to another. When food is
digested its chemical energy is stored in your body and then later
transforms into mechanical energy to move your muscles.
15. What does the law of conservation of energy state?
Energy cannot be created or destroyed, only transferred and
transformed.
16. What is a reference point?
An initial or starting point, used to describe the motion of an object.
17. What is the formula for speed?
Speed = distance/time
18. Solve for speed in a car traveling 50 meters in 100 seconds.
Speed = 50 meters/100 seconds = .5 m/s
19. On a speed vs. time graph what represents an object at rest?
accelerating? decelerating?
At rest- a horizontal line
Accelerating – a slanted line, slopping from lower left to upper right
Decelerating – a slanted line, slopping from upper left to lower right
20. How do you determine net force if forces act in the same direction?
Opposite directions?
If the objects are acting in the same direction, add the net forces
together. If the objects are acting in the opposite directions,
subtract the smaller force from the larger force, the direction will be
that of the larger force.
Organelle
Chloroplasts
Function
Conducts photosynthesis
Plant,
Animal, or
both
Plant
Flexible covering that allows things in
Cell membrane
Vacuole
and out of the cell
Stores water, waste, and food
Both
Both
Golgi
apparatus
Endoplasmic
reticulum
Nucleus
Packages proteins inside the cell before
they are sent to their destination
Both
Smooth: make lipids such as cholesterol
Rough: makes proteins
Directs cell activity; “Brain of the cell”
Both
Both
Protect the plant structural support and
Cell wall
protects the plant cell
Plant
Responsible for assembling the proteins
Ribosomes
of the cell
Energy for the cell; “Powerhouse of the
Mitochondria
cell”
Both
Both
21. List and describe the levels of organization in a multicellular
organism beginning with a single cell.
Cells are organized into tissues. Tissues are groups of similar types
of cells that work together to carry out specific tasks. Organs are
groups of different tissues working together to perform a particular
job. Organ systems are groups of different organs that work
together to complete a series of tasks.
22. Compare asexual and sexual reproduction.
Asexual reproduction is when one parent organism produces
offspring without meiosis and fertilization. Because offspring
inherit all their DNA from one parent, they are genetically identical
to each other and to their parent.
Sexual reproduction is when the genetic materials from two
different cells combine, producing an offspring. Because offspring
inherit their DNA from both parents, there is genetic variation
among offspring.
23. Compare the number of chromosomes in a diploid and haploid cell.
In a diploid cell there are 46 chromosomes. In a haploid cell there
are 23 chromosomes.
Genetics Vocabulary
Definition
homozygous
When two alleles of a gene are the same
heterozygous
When two alleles of a gene are different
A genetic factor that blocks another genetic
dominant
factor; expressed using a capital letter
A genetic factor that is blocked by the
recessive
presence of a dominant factor; expressed
using a lower case letter
phenotype
How a trait appears, or is expressed
genotype
The two alleles that control that phenotype
24. A child has blue eyes, but both of the child’s parents have brown
eyes. Create a Punnett Square below that explains how this is possible.
(B represents brown eye allele, b represents blue eye allele)
B
b
B
Write a sentence to explain the Punnett Square you created.
One possible offspring would be homozygous dominant (BB), 2 would
be heterozygous (Bb) and one would be homozygous recessive (bb)
which is how a child has blue eyes.
25. Where does the energy in an ecosystem initially come from?
From the sun
26. What is the difference between biotic and abiotic factors in an
ecosystem? Give some examples of each.
Biotic factors are all the living or once-living things in an
ecosystem. Examples are populations and communities
Abiotic factors are the nonliving parts of an ecosystem. Examples
are water, light, temperature, atmosphere, and soil.
27. List and describe the three types of symbiotic relationships.
Mutualism: two species in a community benefit from the
relationship.
Parasitism: one species (the parasite) benefits while another (the
host) is harmed.
Commensalism: one species benefits and the other is neither helped
nor harmed
ECR practice: Answer all three questions
1. All matter has both physical and chemical properties, when matter
undergoes a change it can be either physical or chemical.
 Define physical property and chemical property and give an
example for each
 Define physical change and chemical change and give an example
for each
 What makes the difference between a property of matter and a
change in matter?
A physical property is a characteristic of matter that you can
observe or measure without changing the identity of the
matter(boiling/melting point). A physical change is a change in the
size, shape, form, or state of matter that does not change the
matter’s identity(melting ice, mowing the lawn, carving a statue).
Chemical property is the ability of a substance to combine with or
change into one or more new substances( ability to rust, ability to
burn, ability to rot). A chemical change is the change in matter in
which the substances that make up that matter change into other
substances with different chemical and physical properties(burning
a log, rotting apple, rusted bike chain).
2. Sunlight is absorbed by a solar panel on a house. The energy collected
by the solar panel is used to run a blender that chops apples. The apples
are part of a recipe that is cooked in the oven.
 What is an energy transfer?
 What is an energy transformation?
 Explain the scenario above in terms of the types of energy involved
and the energy transfers and transformations involved.
An energy transfer is when energy moves from one object to another
without changing form. Energy transformations is when energy
moves from one object to another and changes its form. The solar
panels collect radiant energy. Radiant energy from the panels is
transformed into electrical energy to the blender. The electrical
energy in the blender is transformed into mechanical energy to chop
the apples. The apples are placed in the oven where thermal energy
from the oven in transferred to the apples, heating them.


3. A heterozygous orange-flowered plant is crossed with a homozygous
purple-flowered plant.
Create a Punnett Square that shows the possible offspring
If orange is a dominant allele and purple is recessive, what color ratio
will the flowers of the offspring plants have? Explain.
D
d
Dd
dd
Dd
dd
There would be a 2:4 chance that the flowers would be orange and a
2:4 chance that the flowers would be purple. Two of the flowers
would be heterozygous resulting in orange flowers and 2 would be
homozygous recessive resulting in purple flowers.