BIOLOGY 1M03 PRACTICE TEST 1
PART A: MULTIPLE-CHOICE QUESTIONS
1. A population of squirrels is analysed for genotypes at a particular allele. In a sample of 20 individuals,
10 have genotype AA, 4 have genotype AB, and 6 have genotype BB. What is the frequency of allele A
in our sample?
a. 50%
b. 60%
c. 70%
d. 80%
e. 90%
2. A population of earthworms lives on an island in the middle of a river. Damming of the river causes
flooding on the island, and only the highest points remain above water, creating several smaller islands
with now-separate earthworm populations on them. The earthworms cannot swim. Which of the
following best describes this event? The earthworm populations:
a. have undergone speciation in allopatry.
b. have undergone speciation in sympatry.
c. have been isolated by dispersal.
d. have been isolated by vicariance.
3. Which pair of taxa are sisters in the model on the left, but not on the model on the right?
a.
b.
c.
d.
e.
1 and 2
3 and 4
5 and 6
All of the above
None of the above
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any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.
4. In the figure below, which group is not a clade?
a.
b.
c.
d.
e.
Ferns
Non-flowering plants (ferns and pines)
Flowering plants (indicated by the dark colour)
Water lilies
Dicots (all flowering plants except water lilies)
5. Which of the following is true about both natural selection and genetic drift?
a. They increase the average fitness of a population.
b. They are random processes.
c. They change the frequencies of alleles.
d. They have strong effects on large populations.
e. They increase variation.
6. Which of the following is the most predictable outcome of increased gene flow between two
populations?
a. lower average fitness in both populations
b. higher average fitness in both populations
c. increased genetic difference between the two populations
d. decreased genetic difference between the two populations
e. increased genetic drift
7. In a scientific experiment, a "control group":
a. is kept in an unchanging environment
b. is left alone by the experimenters
c. is treated similarly to the treatment group, except for one key variable
d. is only subject to one variable at a time
e. is not measured
This practice test is intellectual and academic property of Dr. B. Evans and L. Tiller. Reproduction, distribution, or communication in any form using
any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.
8. Which of the following processes increase genetic variation in a population?
a. natural selection and genetic drift
b. natural selection and mutation
c. natural selection and gene flow
d. gene flow and genetic drift
e. gene flow and mutation
9. A flood followed by a mudslide wipes out most of the ponds where a population of frogs live, killing all
of the frogs in the affected ponds, but not the frogs that live in the remaining ponds. This is an example
of ____________ and we would expect that the population would show _____________ as a result of
this event.
a. a bottleneck effect; reduced genetic variation
b. a bottleneck effect; adaptations to surviving floods
c. gene flow; increased genetic variation
d. gene flow; adaptations to surviving floods
10. Please select the response that presents the most-accurate statement.
a. Mycobacterium tuberculosis populations can evolve drug resistance over time.
b. Evolution by natural selection involves variation among individuals
c. If all individuals in a population were to survive equally effectively, then natural selection would
operate to favour individuals who produce the most offspring.
d. Between 1976 and 1978, a finch population in the Galápagos Islands adapted to drought
conditions.
e. All of the above are correct
11. A two-allele locus known as gene hackman is studied in a snail population that is in Hardy-Weinberg
equilibrium. The frequency for the dominant phenotype is 99%. The frequency for q is:
a. 0.81
b. 0.18
c. 0.1
d. 0.01
e. 0.9
12. There exists a population in which there are three distinct versions of the gene A (a1, a2, and a3).
Originally, each version was present in equal numbers of individuals. Which version of the gene an
individual carries has no measurable effect on its reproductive success. As you follow the population
over a number of generations, you find that the frequency of a1 and a3 drop to 0%. What is the most
likely explanation?
a. There was an increased rate of mutation in organisms that carry either a1 or a3.
b. Mutations have occurred that changed a1 and a3 into a2.
c. Individuals carrying a1 or a3 were removed by natural selection.
d. Random variations led to a failure to produce individuals carrying a1 or a3.
This practice test is intellectual and academic property of Dr. B. Evans and L. Tiller. Reproduction, distribution, or communication in any form using
any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.
13. You are doing experiments to test whether a specific type of acupuncture works. This type of
acupuncture holds that specific needle insertion points influence specific parts of the body. As part of
your experimental design, you randomize your treatments so that some people get acupuncture
needles inserted into the "correct" sites and others into "incorrect" sites. What is the point of inserting
needles into incorrect places?
a. It serves as a negative control.
b. It serves as a positive control.
c. It controls for whether the person can feel the needle.
d. It controls for whether needles are necessary.
14. Which of the following are vestigial structures?
a. Fin of a dolphin and the fin of Ichthyosaurs
b. Human appendix
c. Humerus bone of a bat and a human
d. Tailbone of a monkey
e. Human fingers
15. Which of the following is not true of sympatric speciation?
a. It is speciation that occurs without physical isolation.
b. Allows the divergence of two living species living in the same geographic location.
c. Sympatric speciation is rare or non-existent.
d. Can occur because of isolation due to preference for specific habitats.
e. The soapberry bug is an example of sympatric speciation.
16. Why is speciation by polyploidy much less likely to happen in animals than in plants?
a. Animals have better mechanisms to control meiosis that plants do.
b. Animals rarely self-fertilize, so diploid gametes would have to arise in at least two individuals
of opposite sexes at the same time.
c. Animals are better at recognizing appropriate mates.
d. Animals are more mobile, so populations are less likely to become separated.
17. Given a population that contains genetic variation, what is the correct sequence of the following
events, under the influence of natural selection?
1. Differential reproduction occurs.
2. A new selective pressure occurs.
3. Allele frequencies within the population change.
4. Environmental change occurs.
a. 2,4,1,3
b. 4,2,1,3
c. 4,1,2,3
d. 4,2,3,1
e. 2,4,3,1
This practice test is intellectual and academic property of Dr. B. Evans and L. Tiller. Reproduction, distribution, or communication in any form using
any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.
18. Genetic drift occurs in a population. Which of the following statements might be true?
a. Genetic drift increased the population's fitness.
b. Genetic drift decreased the population's fitness.
c. The population was relatively small.
d. Either b, c, or both.
e. Any of the above statements might be true.
19. Which of the following does not tend to promote speciation?
a. the founder effect
b. gene flow
c. natural selection
d. mutations that cause genetic incompatibility
PART B: SHORT ANSWER
21. How does genetic drift contribute to speciation? Is it likely to contribute most strongly to sympatric,
dispersal-driven, or vicariance-driven speciation? (2 marks)
22. A researcher collects 20 peppered moths and finds that 8 are homozygous for the dark allele (D); 8 are
homozygous for the light allele (L); and four are heterozygous.
a) What are the estimated genotype frequencies in this population (2 marks)?
b) The moths homozygous for L are light, whereas all the others are dark. What type of dominance is seen
in the DL allele? What are the estimated phenotype frequencies for this population (2 marks)?
c) The researchers determine that there are more homozygotes in this population than would be
expected from Hardy-Weinberg assumptions. What is a possible biological reason for this (1 mark)?
This practice test is intellectual and academic property of Dr. B. Evans and L. Tiller. Reproduction, distribution, or communication in any form using
any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.
23. Please consider the following plausible scenarios concerning human evolution and provide one technical
word (in the space provided) to describe the relevant Hardy-Weinberg equilibrium principle, population
genetic factor. (5 marks total)
A) Laws have been established in modern society to define countries, restricting neighbouring
populations to living within borders, so limiting individual interactions between those populations.
_______________________________________ (1 mark)
B) Early in human evolution, individuals tended to remain in the populations, called clans, into which they
were born, to mature and reproduce with other clan members.
_______________________________________ (1 mark)
C) A major difference between modern human societies and ancient ones is the extent to which modern
individuals are protected from harsh environments and hungry predators.
_______________________________________ (1mark)
D) In a very small human population, a new allele rose to high frequency then became fixed even though
it encoded susceptibility to West Nile Virus; the new allele rising and fixing exemplifies …
_______________________________________ (1mark)
E) In some human populations, individuals contain a faulty allele that encodes an incomplete cell surface
protein to which viruses are unable to bind; the allele exemplifies
_______________________________________ (1mark)
This practice test is intellectual and academic property of Dr. B. Evans and L. Tiller. Reproduction, distribution, or communication in any form using
any media is strictly prohibited. Any use of this copyright material must have written expressed permission from Dr. B. Evans and L. Tiller.