Download SBI3C Exam Review

SBI3C Exam Review
Unit 1: Cellular Biology
1. For each of the following statements, indicate whether it is true or false. If false, change the
underlined term to make it true.
F
a. Lysosomes are found only in plant cells. (animal)
T
b. The Golgi apparatus chemically changes fats and proteins and then packages them in vesicles.
F
c. In, chloroplasts, thylakoids are stacked on top of one another forming structures called stroma.
(grana)
F
d. Oxygen, water, and carbon dioxide cannot pass freely through cell membranes. (can)
T
e. An increase in temperature causes an increase in the rate of diffusion.
T
f. Anaerobic respiration can produce ATP even if glucose is not present.
F
g. Ethanol fermentation occurs in muscle cells during periods of strenuous exercise. (lactic acid)
2. State the function(s) of the following cell organelles: nucleus, cell membrane, cell wall,
ribosome, smooth endoplasmic reticulum, rough endoplasmic reticulum, chloroplast,
lysosome, vacuole, Golgi apparatus, mitochondria
Nucleus – control center of the cell & direct cell’s activities
Cell Membrane – keeps organelles inside cell, protective layer, regulates what comes in and
out of the cell (selectively permeable)
Cell Wall – found in plant cells, rigidity gives plants their shape, regulates movement of
water and nutrients in and out of plant cells
Ribosome – makes protein for the cell
Smooth ER – makes fat molecules
Rough ER – makes protein molecules
Chloroplast – found in plant cells, contains ingredients to conduct photosynthesis
(chlorophyll)
Lysosomes – found in animal cells, contains enzymes that break down food, waste, bacteria
and viruses, also plays a role in the immune system
Vacuole – sacs that contain nutrients, water and proteins; keeps cell membrane pressed up
against cell wall (gives cell turgidity)
Golgi apparatus – receives fat and protein molecules from Smooth/Rough ER, chemically
packages them into vesicles and transports it to cell membrane where it will be released to
the extra-cellular fluid
Mitochondria – makes energy for the cell
3. What are the major roles of carbohydrates, fats and proteins?
Carbohydrates – source of energy
Fats – source of energy (including long-term storage), insulation, protects vital organs,
component of cell membrane, dissolves fat-soluble vitamins
Proteins – build and repair cells, act as enzymes in chemical reactions
4. A piece of carrot is placed on a solution. Its mass:
a. Increases. What kind of solution was it? Hypotonic
b. Decreases. What kind of solution was it? Hypertonic
c. Remains the same. What kind of solution was it? Isotonic
5. Would a plant cell burst in a hypotonic solution? Explain why or why not.
Hypothetically, yes, as water would be coming in to offset the concentration differences, which
causes the cell to expand & possibly burst. However, in reality, it is not really the case. The plant
cell has a thick tough outer cell wall made of cellulose, a tough carbohydrate. This allows for the
plant to expand to handle the pressure (hence, turgidity) but it will not burst unless placed it is an
extremely hypotonic solution that it cannot withstand the pressure.
6. What is the difference between aerobic and anaerobic respiration in terms of definition,
location of this in the cell, energy output (ATP) and real-world examples.
7. What are the word equations for cellular respiration and photosynthesis?
Cellular respiration: Glucose + Oxygen  Carbon Dioxide + Water + Energy
Photosynthesis: Carbon Dioxide + Water + Energy  Glucose
Unit 2: Microbiology
1. Compare and contrast eukaryotes and prokaryotes in terms of cell structures.
-
Eukaryotes
nucleus present
many chromosomes
mitochondria present
chloroplasts can be present
complex flagella
-
Prokaryotes
nucleus absent
usually a single chromosome
mitochondria absent
chloroplasts absent
simple flagella
2. What are archaebacteria? How are they different from eubacteria?
Archaebacteria is a group of bacteria that is older than today’s bacteria (eubacteria). ‘Archae’
means early or primitive. They are different from eubacteria in that they live in extreme
environments and most of them can live without oxygen. There are three groups of
archaebacteria:
Thermophiles – live in extremely hot environment (eg. Hot springs)
Methanogens – live in environments without oxygen (high in CO2, methane gas,
hydrogen gas, etc) (eg. Deep sea vents)
Halophiles – live in salty environments (eg. Salt flats)
3. Viruses have two reproductive cycles. What are they and how are they different?
Viruses can reproduce through the lytic cycle or the lysogenic cycle.
In the lytic cycle, after the virus is replicated, the host cell dies when the cell lyses (breaks).
In the lysogenic cycle, the virus continues to replicates in a manner similar to mitosis without
harming the host cell. It will only harm the host cell if an environment stimulant triggers
activation of the lytic cycle, in which the host cell will then die.
4. Classify the following as Algae (Plant Protist), Protozoa (Animal Protist), Fungi-like Protist,
Bacteria or Virus. Explain your classification choice based on the characteristics of the cell.
Bacteria (flagella, rod-shaped,
lack of complex organelles
inside cell)
Algae (green chlorophyll
pigment = plant protist, thick
outer wall = cell wall)
Protozoa
Paramecium (presence of oral
groove). Animal-protist
because no chlorophyll
present
Bacteria (spirilla) – lack of
complex cell structures
Protozoa (amoeba)
Pseudpod seen
Fungi-like protist (water
mold) – can see spores
Green Algae (green chlorophyll pigment,
thick outer wall = cell wall)
Unit 3: Genetics
1. What are the roles of mitosis and meiosis?
Mitosis – growth, repair and development of cells
Meosis – sexual reproduction and genetic variety
2. Identify the following stages of mitosis and explain how you know it is that particular stage.
Anaphase – chromosome pairs are pulled apart and
Move towards the poles using the spindle fibres
Prophase – chromosome pairs still intact
within nuclear membrane. They are visible,
but the nuclear membrane is disintegrating
so that the chromosomes can move towards
the middle of the cell for Metphase.
3. Identify the following stages of meiosis if it starts off with 4 pairs of chromosomes and
explain how you know it is that particular stage. Make sure to indicate if it is in the first stage
(Meiosis I) or the second stage (Meiosis II).
Metaphase 1 – four chromosome pairs still
seen (so Meiosis I), lined up along the
equatorial plate, have yet to be pulled apart at
this point
Prophase 2 – prophase because chromosomes
are within nuclear membrane, but nuclear
membrane is disintegrating to prepare for
metaphase. It is Meiosis 2 because # of
chromosome pairs has been halved (4  2)
4. Freckles are a dominant trait. Patty is homozygous dominant for freckles, while Charlie is
homozygous for no freckles. Draw a Punnett square predicting the probability (%) if their
children will have freckles.
Let F = freckle and f = no freckles. Patty is FF and Charlie is ff
F
F
f
Ff
Ff
f
Ff
Ff
100% Ff
100% freckles (therefore, their children will have freckles)
5. Cystic fibrosis is a recessive genetic disorder. Ron is homozygous dominant and Nancy is a
carrier (Ff) of cystic fibrosis. Use a Punnett square to predict the probability (in %) that one
of their children will have cystic fibrosis? Show all work and box your final answer.
Let F = normal and f = cystic fibrosis. Ron is FF and Nancy is Ff
F
f
F
FF
Ff
F
FF
Ff
50% Ff and 50% FF
100% normal (but 50% of children will be carriers)
None of their children will have cystic fibrosis.
6. Woody Guthrie, who wrote This Land is Your Land, was heterozygous for Huntington’s
disease (Hh). His wife was homozygous recessive and perfectly normal. Huntington’s
disease is caused by a latent dominant gene, meaning that it is not phenotypically
(physically) expressed until later in life. Dominant disease genes are expressed in
homozygous dominant and heterozygous people (HH or Hh). Draw a Punnett square for the
cross between Woody and his wife.
Let H = Huntington’s disease and h= normal. Woody is Hh and Woody’s wife is hh.
H
h
h
Hh
hh
h
Hh
hh
50% Hh and 50% hh
50% Huntington’s disease and 50% normal
7. Larry and Lola Little have achondroplasia, a form of dwarfism. Both are heterozygotes. Their
son, Big Bob Little, is 7’1”. Use a Punnett square to show how Big Bob got his genotype.
Let a = normal and A= achondroplasia. Larry is Aa and Lola is Aa
A
a
A
AA
Aa
a
Aa
aa
25% AA, 50% Aa, 25% aa
75% achrondroplasia and 25% normal
Because both parents had a recessive allele (normal, a), there was a 25% chance that their child
would not have achondroplasia. In this case, Big Bob ended up getting this genotype (aa) so he
does not have dwarfism.
Unit 4: Anatomy of Mammals
1. Fill in the chart below, stating a function for each organ in the digestive system, including
accessory organs:
Organ
Esophagus
Stomach
Liver
Pancreas
Small Intestine
Salivary Glands
Gall bladder
Large Intestine
Function
Muscular tube that connects mouth to stomach. Food moves down using
peristalsis, a form of mechanical digestion.
Muscle layers churn and mix food. Chemical digestion occurs here from
gastric juices. Some absorption of water, alcohol and aspirin also occurs
here.
Secretes bile for fat digestion that would occur in the small intestines. It
also stores carbohydrates/vitamins and eliminates toxic substances (the
liver is a detoxifying agent).
Makes pancreatic juices to be released into the small intestines to digest
carbohydrates, proteins and fats. It also produces bicarbonate to control
acidity of the stomach.
Chemical digestion of protein, fats and carbohydrates occurs here. It also
absorbs nutrients.
Secrete saliva which contains amylase, an enzyme that helps digestion of
carbohydrate when chewing food.
Stores and concentrates bile that comes from the liver. It releases this bile
into the small intestines which helps with fat digestion.
Secretes movement of mucus to help movement of food; storage of
unused solid material till it’s ready to be voided
2. How does the pulmonary circuit and systemic circuit work?
Both circuits rely on each other in order to function. Oxygen-poor blood coming from the
right side of the heart is pumped through veins to the lungs, where it becomes oxygenated
(this oxygen comes from the oxygen we inhale). The blood, now oxygen-rich, returns to the
left side of the heart through arteries. The heart pumps out this oxygen-rich blood to the body
tissues where the oxygen will be used. Once the tissue uses up the oxygen, the blood returns
back to the heart, oxygen-poor to continue the cycle.
3. What enzymes are involved in the digestion of: a) carbohydrates, b) fats, and c) proteins
Carbohydrates – amylase, maltase, pancreatic amlyase
Fats – lipase
Proteins – peptidases/pepsin, trypsin
4. What is the role of the diaphragm in the respiratory system? How does it work during
inhalation and exhalation?
Contraction and relaxation of the diaphragm allows for inhalation and exhalation of air during
respiration. During inhalation, the diaphragm contracts and moves downward, causing the rib
cage to move outward. The pressure decreases, causing air to move into the lungs. During
exhalation, the diaphragm relaxes and moves upwards, causing the rib cage to move inward. The
pressure increases, causing air to leave the lungs.
5. How does the respiratory system work in terms of inspiration and expiration? Name all the
organs involved.
See notes on pathway of O2 into the lungs, and back up again with CO2.
6. Compare and contrast between the following pair of terms:
a. Systole and diastole – Systole and diastole are stages in the cardiac cycle of the
circulatory system. It has to do with the contraction of the heart and is related to
blood pressure (force of blood against the walls of arteries). The diastole is the
relaxation phase in which blood enters the atria and flows in the ventricle = LUBB
sound with the opening of the valve between the atria and ventricles. This is when the
blood pressure is low. The systole is the contraction phase where the ventricles are
filled with blood and pushed out with great force. The valve between the atria and
ventricles are closed to accommodate this pressure change. The pressure is high here
and contributes to the DUBB sound.
b. Arteries and veins – arteries and veins are both part of the circulatory system. They
are kinds of blood vessels. Arteries carry oxygen-rich blood away from the heart to
the body tissues. They are red in colour due to the oxygen. The walls of arteries are
thicker than veins. Veins, on the other hand, carry oxygen-poor blood back to the
heart from the lungs or body tissues. They are blueish in colour due to the lack of
oxygen. Their walls are thinner.
c. Atria and ventricles – are both part of the circulatory system. They are kinds of
chambers seen in the heart (there are two atria and two ventricles). Atria receives the
blood from either the lungs or body tissues. They send this blood into its
corresponding ventricle through a valve. The ventricle then pumps this blood out with
great force to either the lungs or body tissues. The pressure is stronger with the
ventricle and weaker with the atria. The atria has thinner walls compared to the
ventricle, which is thicker.
d. Red blood cells and white blood cells – they are both components of blood in the
circulatory system. Red blood cells are disc-shaped and have a binding site that is
specific to the binding between hemoglobin protein and oxygen molecules. They are
reddish in colour and are responsible for carrying oxygen throughout the body
essential for life. White blood cells, are more irregular in shape (of varying nature),
and its function is related to the immune system. WBCs are responsible for protecting
our bodies against pathogens, bacteria and viruses. White blood cells do have a
nucleus but red blood cells do not (in order to conserve space for binding of oxygen
molecules to hemoglobin).
7. How does gas exchange occur between the alveoli and capillaries?
Oxygen-poor blood is carried from the right side of the heart to the lungs through veins. This
vein is further divided into capillaries. This capillary network is brushed up against the alveoli
(air sacs) of the lungs. The oxygen we inhale makes its way down to the alveoli. The oxygenpoor blood in the capillaries has high CO2 whereas the alveoli have low CO2. Therefore,
diffusion of CO2 molecules occurs, moving from high to low concentration. Meanwhile, the
alveoli are high in O2 and the capillaries (O2 poor) is low in O2. Therefore, oxygen diffuses from
the alveoli to the capillaries. This is what we mean by gas exchange of O2 and CO2 between the
alveoli and capillaries. The blood, now O2 rich, thanks to the alveoli, goes back to the heart
through arteries to be pumped out to the body tissues.
8. The table below shows what happens when we inhale.
Gas
Inhaled
Oxygen (O2)
20.71%
Carbon dioxide (CO2)
0.04%
Water (H2O)
1.25%
Exhaled
14.6%
4.0%
5.9%
a. What gas is removed from inhaled air? Oxygen
b. What two gases are added to inhaled air than exhaled? Carbon dioxide and water
c. Which gas shows the greatest difference in percent (%) between inhaled and exhaled air?
Oxygen
Unit 5: Plants in their Natural Environment
1. There are four groups of plants. Each plant can be EITHER vascular or non-vascular and
EITHER seed or non-seed. Check off the appropriate columns below:
Vascular
Non-Vascular
Seed
Non-Seed
Moss
X
X
Fern
X
X
Gymnosperm
X
X
Angiosperm
X
X
2. What is plant biodiversity and what factors can cause biodiversity to go down? What are the
consequences of decreasing plant biodiversity?
Plant biodiversity refers to the number of different plant species and the number of individual
plants within each species. When plant biodiversity is affected in a negative manner, it is a
domino effect for other natural species. For example, a particular animal species may rely on
only one plant as a source of food. When that food source is eliminated, the animal species is
at risk for extinction.
3. Compare and contrast monocots and dicots using varying characteristics (eg. Leaf pattern,
arrangement of vascular bundles, number of cotyledons, etc)
Monocots
Dicots
- 1 cotyledon
- 2 cotyledons
- leaf veins run parallel to each other
- leaf veins in net-like arrangement
- vascular bundles scattered throughout
- vascular bundles arranged in a ring
in random arrangement
- number of flower petals are factors of
- number of flower petals are factors of
4’s and 5’s
3’s
- cannot see vascular bundles clearly in
- can see vascular bundles in leaf cross
leaf cross section
sections
- taproot
- fibrous root
4. Match the parts of a plant to their function by drawing lines between the columns.
1. xylem (f)
a) Transports sugar and other food
2. cambium (d)
b) Provides first seed leaves to become a plantlet
3. stem (e)
c) Protective wax layer
4. stomata (h)
d) Makes new xylem and phloem
5. cuticle (c)
e) Allows for transport of nutrients and water through veins
6. root (g)
f) Transports water and dissolved nutrients
7. phloem (a)
g) Anchors plant to ground
8. cotyledon (b)
h) Allows for exchange of gases and water molecules
5. Give TWO functions for each part of the plant:
a. Roots – anchors plant into ground, holds soil in its place, absorbs water and nutrient
from soil to be delivered up to the plant stem and leaves
b. Leaves – main photosynthetic organ, means of water conservation through waxy
cuticle and stomata, gas exchange through stomata
c. Stems – plant support system (holds up leaves and branches), vascular tissues allow
for transport of food, water and other dissolved minerals essential for life
6. Answer the following questions about photosynthesis:
a. What is it? Plant cellular respiration
b. Why is it so important to us? Photosynthesis enable plants to make oxygen that is
necessary for life. Moreover, it allows plant to make food for themselves (autotrophs)
and for us (heterotrophs). Without photosynthesis, there would be no food and no
oxygen.
c. Where does it occur? In the thylakoid of the chloroplast (the chlorophyll pigment
helps stimulate this)
d. What is the word equation for this process?
Carbon dioxide + water + light energy  oxygen and glucose