PRACTISE QUESTIONS BIOL 1001 W2012 Key
The easier questions on here are not representative of test questions, but are to allow you to ensure that you
understand the basics. If you don’t understand a question, I would suggest you talk to some friends about it.
Please note the term trait and character are used interchangeably here.
I do not have practice questions for the nature of science section; however, we did many questions about this in class
and it has been brought up repeatedly since then.
1. Artificial selection is likely to produce p opulation-level changes most quickly in organisms with:
a. a small litter size.
b. a short generation time.
c. a large body size.
d. a large genome.
e. a long life span.
2. Malthus’s Essay on the Principle of Populations was key to both Darwin and Wallace’s formulation of a mechanism
for evolutionary change. Which of the following statements best summarizes Malthus’s idea?
a. Populations produce more offspring than their environment can support, resulting in competition for resources.
b. Populations always produce less offspring than their environment can support, resulting in decreased
c. Populations of animals are able to pass to their offspring characteristics acquired in their lifetimes.
d. On average, populations produce the number of individuals that their environment can support.
e. Populations that are isolated cannot support themselves because they cannot generate resources.
3. Many crustaceans (e.g., lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl
under their shells and are not used in swimming. This is an example of
a. artificial selection.
b. an extinction.
c. an acquired characteristic.
d. a vestigial trait.
e. natural selection.
4. The upper forelimbs of bats (mammals) and birds (classified with reptiles) have fairly sim ilar skeletal structures.
However, bat wings have a thin flap of skin stretched between the bones of the fingers and the arm, while bird wings
consist of feathers extended all along the arm. How would you describe these relationships?
a. The forelimb skeletons of birds and bats are homologous, as are the wings.
b. The forelimb skeletons of birds and bats are due to convergent evolution, whereas the wings are homologous.
c. The forelimb skeletons of birds and bats are homologous, whereas the wings are due to converg ent evolution.
d. The forelimb skeletons of birds and bats are due to convergent evolution, as are the wings.
5. Which of the following is the best modern definition of evolution?
a. descent without modification
b. change in allele frequencies in a population over time
c. survival of the fittest
d. inheritance of acquired characters
6. How did Hutton & Lyell’s ideas influence Darwin’s thinking about evolution?
7. Which of the following observations helped Darwin shape his concept of descent with modification?
a. Species diversity declines farther from the equator.
b. Fewer species live on islands than on nearest continents.
c. Birds can be found on islands located farther from the mainland than the birds’ maximum nonstop flight
d. South American temperate plants are more similar to tropical plants of South America than to the te mperate
plants of Europe.
e. Earthquakes reshape life by causing mass extinctions. PRACTISE QUESTIONS BIOL 1001 W2012 Key
8. Darwin described evolution with the phrase “descent with modification.” What did he mean?
a. Evolution takes a long time – it isn’t an instantaneous process.
b. Evolution is not a “special” process – it’s a natural phenomenon that is going on today.
c. Closely related species are similar at the genetic, developmental & structural levels.
d. Populations living today are related (genetically) to populations that lived in the past, but they aren’t identical.
e. Both C & E apply.
9. When measuring genetic variation, the appropriate size unit is:
10.A phenotype of an organism is:
a. Its genetic constitution, which governs its traits
b. Chronological expression of its genes
c. Physical expression of its genotype
d. Form it achieves as an adult
11.In a population, there are two alleles of the A gene (A1 & A2). You know that the frequency of the A1 allele is 0.4.
Calculate the frequency of the other allele. A2 = 0.6 If A2 encodes a phenotype that is dominant to A1, what
proportion of the population will show the A2 phenotype? 2pq+q2 = 2(0.4)(0.6) + (0.6)2 = 0.48 + 0.36 = 0.84
12.7. In a population, there are two alleles of the A gene (A1 and A2). Genotypes of the A gene are found a the
following frequencies: A1A1 = 0.54; A1A2 = 0.38; A2A2 = 0.08. What is the observed frequency of the A1 and A2
A. 0.73; 0.27
B. 0.54; 0.45
C. 0.63; 037
D. 0.485; 0.515
E. 0.392; 0.608
13.The Hardy–Weinberg principle of genetic equilibrium tells us what to expect when a sexually
a. reproducing population is
b. decreasing with each generation.
c. increasing with each generation.
f. not evolving.
14.In what sense does the Hardy-Weinberg principle act as a null hypothesis?
a. It is the starting point of all evolutionary studies.
b. It specifies the conditions that need to be controlled in an evolutionary study.
c. It specifies what genotype frequencies should be, given measured allele frequencies.
d. It specifies what should be observed if no evolution is currently occurring at a particular gene.
15.What changes DNA but has no impact upon the phenotype of an individual.
a. beneficial mutations
b. neutral mutations
c. directed mutations
d. chance mutations
e. all of these
16.The source of new alleles in a population is
a. natural selection.
e. genetic drift. PRACTISE QUESTIONS BIOL 1001 W2012 Key
17.Some biologists encapsulate evolution by natural selection with the phrase “mutation proposes, selection disposes”.
Explain what they mean, using the formal terms you have learned to describe evolutionary processes.
18.Of all the mutations that occur in a population, why do only a small fraction become widespread among the
19.In 1986 a nuclear power accident in Chernobyl, USSR (now Ukraine) led to high radiation levels for miles
surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and
evolutionary biologists have been studying rodent populations in the Chernobyl area e ver since. Based on your
understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations
following the accident?
a. Mutation by itself led to major changes in rodent physiology over time.
b. Mutation led to increas ed genetic variation and a higher rate of evolutionary change.
c. Mutation caused genetic drift and decreased fitness.
d. Mutation caused the fixation of new alleles.
20.Why are mutations important in evolution, when most mutations are harmful?
21.Natural selection can only act on traits:
a. that reduce mortality
b. that confer a reproductive advantage.
c. that are acquired in an individual's lifetime.
d. that are heritable.
e. that are adaptive.
22.The intermediate form of a trait is favored when __________ selection occurs
e. none of these
23. When a population’s allele frequencies are shifting in a consistent direction, ______ selection is occurring