Biology 30 Course Review
Chapter 13
1. Describe the reflex arc, explaining how the message is sent along the neuron and to adjoining
neurons.
Chapter 14
1. A person is near a small explosion. Describe how the sensory information travels to the brain.
Chapter 15
1. Hypothyroidism occurs when the thyroid gland decreases production of thyroid hormones
resulting in the slowing of body metabolism.
(a) Make a list of symptoms that would help a physician identify hypothyroidism.
(b) Why might low thyroid hormone secretions lead to an enlarged thyroid gland?
(c) Suggest a possible treatment for hypothyroidism.
(d) One of the most useful developments in laboratory diagnostics in recent years has been the
advent of new high-sensitivity tests for thyroid stimulating hormone (TSH). TSH measurement is
useful in measuring whether patients who receive thyroxine for hypothyroidism are getting the
right dose. The normal range is between 0.4 to 4.0 mU/L. Would a low or high reading of TSH
signal too little thyroid hormones is given? Give reasons for your prediction.
2) Hormones and Blood Sugar Levels
Lab Exercise pg 483
3) Hormones and Stress
a) Alex was walking home after school when a large, vicious-looking dog came around
the corner and started growling and snapping at him. He was only a few houses from home, so
he tried to make a run for it and the dog chased him. Explain what is happening in his body on a
hormonal level.
b) Karen is studying for her biology diploma that is two weeks away. She keeps confusing
ADH and ACTH and is worrying that she will fail. Explain what is happening in her body on a
hormonal level.
4) Pg 484 #2-4, 6, 7
5) Ashley has been diagnosed with hyperthyroidism and is unsure what that means for her body.
Explain what is happening in her body on a hormonal level and what symptoms she can expect to
experience. What hormonal supplements could she take to reverse this?
6) As women age, they suffer from decreased bone density. Describe the affects of calcitonin and
parathyroid hormone on calcium levels and bone density.
7) Pg 489 #3, 8, 11
8) Jared was training for a marathon and was nearing the end of his 30 km run. He was close to
beating his best time and didn’t want to stop for a drink of water even though he was sweating
and really thirsty. Explain the mechanism involved in this situation that would prevent his blood
from becoming too dehydrated.
9) Diabetes review
a) Compare Types 1 and 2 of Diabetes Mellitus.
b) Compare Diabetes Mellitus to Diabetes Insipidus.
Chapter 16
1. Design an experiment to demonstrate the independent functions of the interstitial cells and
seminiferous tubules of the testes.
2. Anabolic steroids act in a similar fashion to testosterone by turning off secretions of
gonadotropic hormones. What effects do anabolic steroids have on secretions of testosterone?
Explain your answer.
3. The seminal vesicle, prostate gland, and Cowper's gland contribute secretions to the semen.
How would reproduction be affected should secretions from these glands be inhibited?
4. A 1988 article reported that prenatal testing had been banned in South Korea following a rise in
male births. Seoul hospitals noted the change in the ratio of male to female births from 102.5
males for every 100 females, to 117 males for every 100 females. One statistician claimed that
the change in ratio could be attributed to the selection of male fetuses following prenatal testing.
In India, doctors have been told not to disclose the sex of a child following amniocentesis testing.
Consider the implications for a society that attempts to select the sex of unborn children.
5. The embryo is sensitive to drugs, especially during the first trimester. In the late 1950s a drug
called thalidomide was introduced in Europe to help prevent morning sickness. Unfortunately, the
drug altered the genes regulating limb bud formation in developing embryos. Before the drug
could be withdrawn from pharmacies, children were born with lifelong disabilities. Although drugs
such as thalidomide are no longer available, a great debate centers around drugs that may have
less pronounced effects on the fetus. Some evidence suggests that tranquilizers may cause
improper limb bud formation. Even some acne drugs have been linked to facial deformities in
newborns, and the antibiotic streptomycin has been associated with hearing problems. Explain
why the embryo is so sensitive to drugs.
Chapter 17
1. What is cloning?
2. Draw a diagram of meiosis to show how a female child is produced from the union of a sperm
and an egg. (show the formation of the sperm and egg)
3. Consider what would happen if you remained a single cell for your entire life. How would your
life as a single cell organism differ from that of a multicellular organism?
4. What evidence suggests that one of your nerve cells carries the same number of
chromosomes and the same genetic information as one of your muscle cells?
5. Explain why orchids cloned from tissue cultures are similar.
6. Explain why sexual reproduction promotes variation.
7. Some herbicides kill weeds by increasing the rate at which they grow.
(a) Design an experiment that would test this hypothesis.
(b) What is the control used in your experiment?
(c) Identify the manipulated (independent) variable and responding (dependent) variable for
your experiment.
(d) How will you measure the rate of cell division?
Use the following information to answer questions 8 to 10.
A researcher compared the growth rate of malignant cells and normal cells in mice. The number
of cells present in an area of 1 cm 2 was counted every two days over a period of two months.
8. Which of the graphs shown above represents the data collected? Explain your answer.
9.
Why did the researcher need both malignant cells and normal cells?
10. Suggest three environmental conditions that the researcher needed to control while culturing
these cells.
11. The cells in the outermost layer of your skin have no nucleus. A moisturizer claims to restore
and rejuvenate these cells, meaning that new cells are grown. (a) Would these skin cells be
capable of producing other skin cells? (b) How would you go about testing the claim?
12. Ionizing radiation, such as X rays, breaks apart chromosomes. The following figure shows the
effects of irradiation on a cell in metaphase. Food scientists will sometimes irradiate fruit and
vegetables to improve shelf life. How does irradiation help preserve food?
13. A girl with malignant melanoma, a cancer of the pigment cells of the skin, had one of her
cancer cells grafted onto the skin of her mother. Scientists believed that the invading cancer cell
from the dying child would stimulate the production of antibodies in the mother. The invading
cancer cells would be destroyed by the antibodies, which the scientists would then harvest and
transfuse into the blood of the dying girl. The experiment did not work. The young girl died a few
days after the procedure. However, the true failure of the experiment was not known until some
months later. The mother developed skin cancer, which killed her. This situation raises moral and
ethical questions. How might the following factors affect your decision about treatment? . risks
versus benefits . quality of life during and after treatment
14. According to one report, the incidence of infertility appears to be increasing in countries like
Canada. The sperm count in males has fallen more than 30 % in the last half century and is
continuing to fall. Although there is no explanation for this phenomenon at present, environmental
pollution is suspected. Suggest other reasons for decreased fertility in males and females.
15. A technique called egg fusion involves the union of one haploid egg cell with another. The
zygote contains the full 2n chromosome number and is always a female. Discuss the implications
to society if this technique were applied to humans.
Chapter 18
1. Explain the difference between a dominant and a recessive condition. Provide an example.
2. Two pea plants are cross-bred. Using a Punnett square and probability analysis, you predict
that 3/4 of the offspring will be tall. However, less than 1/4 grow to be tall. What other factors can
affect phenotype? How much trust should be put on probability calculations?
3. Explain in your own words the meaning of dominance, codominance, and incomplete
dominance.
4. Multiple alleles control the intensity of pigment in mice. The gene D 1 designates full colour, D
2 designates dilute colour, and D 3 is deadly when homozygous. The order of dominance is D 1 >
D 2 > D 3 . When a full-colour male is mated to a dilute-colour female, the offspring are produced
in the following ratio: two full colour to one dilute to one dead. Indicate the genotypes of the
parents.
5. A geneticist notes that crossing a round-shaped radish with a long-shaped radish produces
oval-shaped radishes. If oval radishes are crossed with oval radishes, the following phenotypes
are observed in the F 2 generation: 100 long, 200 oval, and 100 round radishes. Use symbols to
explain the results for the F 1 and F 2 generations.
6. Black coat colour ( B ) in cocker spaniels is dominant to white coat colour ( b ). Solid coat
pattern ( S ) is dominant to spotted pattern ( s ). The gene for pattern arrangement is located on a
different chromosome than the one for colour, and the pattern gene segregates independently of
the colour gene. A male that is black with a solid pattern mates with three females. The mating
with female A, which is white and solid, produces four pups: two black, solid, and two white, solid.
The mating with female B, which is black and solid, produces a single pup, which is white,
spotted. The mating with female C, which is white and spotted, produces four pups: one white,
solid; one white, spotted; one black, solid; one black, spotted. Indicate the genotypes of the
parents.
Chapter 19
1. Huntington's chorea is a dominant neurological disorder that usually makes its presence
known when a person is between 35 and 45 years of age. Some sufferers of Huntington's chorea
do not show symptoms until they are well into their sixties. Speculate on why the later
development of this disease has led to its increased frequency in the population.
2. Explain the significance of locating the cystic fibrosis gene.
3. Duchenne muscular dystrophy is caused by a sex-linked recessive allele. A new test is able
to detect the level of specific enzymes in carriers, who are unaffected by the disease. Carriers,
who are heterozygous, have only one copy of the normal allele and thus produce fewer of these
enzymes. Researchers are working on a technique that would allow carriers to produce viable
sperm or egg cells that contain the normal allele. Egg or sperm cells with the recessive Duchenne
allele would not develop. Discuss some of the implications to society if this procedure were to
become available in the near future.
4. Norrie's disease is associated with blindness. It is inherited as a recessive, X-linked trait. A
man who does not have Norrie's disease is married to a woman who is a carrier. Based on this
information,
(a) What is the probability that the couple's first child will have Norrie's disease?
(b) What is the probability that the couple's first child will be a normal daughter?
Chapter 20
1. Explain why a cell's DNA does not move freely about the cytoplasm.
2. Describe the role of the following molecules in protein synthesis: ribosomes, mRNA, tRNA.
3. Compare DNA and RNA and outline their similarities and differences.
4. In a hypothetical situation, 85 amino acids exist and there are still only 4 nucleotides found in
nucleic acid. Calculate the minimum number of nucleotides required to code for this large number
of amino acids. What is the maximum number of amino acids your answer would code for?
5. Typically, DNA is double stranded and RNA is single stranded. Hypothesize reasons to
account for this difference in structure, based on the function of each molecule in the cell.
6. What would likely occur if:
(a) single-stranded binding proteins were malfunctioning during DNA replication?
(b) DNA polymerase III was inactivated?
(c) DNA polymerase I was malfunctioning?
7. Refer to the diagram of DNA replication ( Figure 1 ). Which letter indicates the 3' ends of
molecules, and which indicates the 5' ends?
9. If you had a mixture of single-stranded DNA fragments, all four nucleotide bases, and DNA
polymerase III, what additional component would need to be added to ensure replication? Explain
why there would not be any discontinuous replication occurring in the test tube.
10. DNA is the hereditary material of all life. Comment.
11. For each pair of mutations, identify which type would be the least harmful to an organism
and explain why:
(a) substitution versus deletion
(b) inversion versus substitution
12. Describe the consequences to protein synthesis if the following were inactivated:
(a) RNA polymerase
(b) tRNA
(c) ribosomes
13. The following polypeptide sequence has been obtained from a protein found in eukaryotic
cells:
met-gly-pro-val-arg.
(a) List a possible mRNA sequence that may have coded for this protein.
(b) Explain why more than one sequence may exist.
(c) How does variability in the mRNA offset mutations? Where does this variability originate?
Chapter 21
1. Use the term allele frequency to explain how biologists define and quantify evolution within a
population.
2. During the fall migration, several Canada geese stop at a river near a good food source and
then nest there the following spring. Because of the abundance of food, this population of geese
stops migrating. What effects, both immediate and long-term, might this situation have on the
gene pools of the original and founder populations?
3. Find and describe an example that does not appear in the text in which the founder effect has
altered the allele frequency of a human population.
4. Why might evolutionary biologists be more concerned with the study of population genetics
than the study of the simple inheritance of alleles by offspring from their parents?
5. Relate, with an example, how random chance can have a greater effect on small populations
than on larger populations.
6. Describe one or more sexual selection traits in
(a) moose
(b) mallard ducks
(c) fiddler crabs
(d) lions
Use the following information to answers Questions 7 and 8.
Genotype Frequencies for Three Selected Populations
Population
X
Y
Z
AA
25
40
2
Aa
50
20
16
aa
25
40
32
7. For each population, determine the expected genotype frequencies of the next
generation.
8. Which population is not in Hardy-Weinberg equilibrium? Explain whether this population
is being influenced by disruptive selection.
9. In parts of Africa , the incidence of sickle cell anemia is 1 in 64. Use the Hardy-Weinberg
equation to estimate the genotype frequencies in this population.
10. With reference to the Hardy-Weinberg equilibrium, explain how each of the following
situations would result in evolutionary change:
(a) In 1996, only 80 adult piping plovers, an endangered bird species, nested in the entire
province of Nova Scotia .
(b) Each year, new strains of the influenza virus cause human disease.
(c) In 1976 and 1977, a severe drought and change in food availability favoured the survival
of ground finches ( Geospiza fortis ) with larger bill sizes over the survival of those with
smaller bills.
Chapter 22/23
1. In April, a population of frogs in a local ravine had a population of 42, which was increased in
May by 263 tadpoles. Pesticide runoff killed 26 tadpoles and predators consumed eight frogs. In
July, construction workers began clearing the ravine and ran over 12 frogs. Calculate the per
capita growth rate of the frogs in the ravine from April to August.
2. Although zebra mussel populations are growing exponentially in many parts of the Great
Lakes , their numbers are decreasing naturally in certain locations. Suggest possible reasons for
such a decline.
3. The density of boreal owls was found to be about 0.005/ha in Kluane National Park and
0.001/ha in both northern Alberta and northern Ontario . What does this suggest about the
carrying capacity of these environments?
4. Describe the concept of carrying capacity and explain its role in population dynamics.
5. Identify and describe ways in which the decline of resources in an ecosystem can affect the
growth rate of a population in that ecosystem.
Use the following information to answer Questions 6 to 7.
6. Label the different phases of this growth curve.
7. Suggest possible reasons for the decline in carrying capacity at time D.