SBI3U – Biology
Evolution Unit Test
Name:__________________
Date:___________________
Multiple Choice: Questions
Short Answer: Questions
Total of 7 Pages
Multiple Choice Identify the letter of the choice that best completes the statement or answers
the question.[1 mark each]
1. Which statement does not reflect Darwin’s theory of evolution by natural selection?
a. Excess numbers of individuals are produced in each generation.
b. All members of a population have an equal opportunity to reproduce.
c. Members of the same population must compete for essential resources to survive.
d. Resources in the environment are limited.
e. Population levels tend to remain unchanged.
2. Which process does not contribute to the variability of a population over time?
a. random mating
b. gene flow
c. mitosis
d. mutation
e. geographic separation
3. What key concept about population growth did Malthus contribute to Darwin’s thinking?
a. Populations grow linearly.
b. Populations grow exponentially.
c. Populations grow without limit.
d. Populations grow arithmetrically.
e. none of the above
4. What might happen to a species of insect if it lacked sufficient genetic variation to adapt to a
changing environment?
a. It might acquire genes through evolution.
b. It might become extinct.
c. It might evolve into a less complex form.
d. It might evolve into a more complex form.
e. It might mutate to acquire appropriate genes.
5. What is required for natural selection to occur?
a. variation within a species
b. variation between species
c. some artificial means of selecting traits
d. no change in environmental conditions
e. all of the above
6. In science, the term theory generally applies to an idea that:
a. Is a speculation lacking supportive observations or experiments.
b. Attempts to explain many related phenomena
c. Is synonymous with what biologists mean by a hypothesis
d. Is so widely accepted that is considered a law of nature
e. Cannot be tested
7. In evolutionary terms, an organism's fitness is measured by its
a. health
b. contributions to the gene pool of the next generation
c. mutation rate
d. genetic variability
e. stability in the face of environmental change
8. Which of the following would provide the best information for distinguishing phylogenetic
relationships between several species that are almost identical in anatomy?
a. The fossil record
b. homologous structures
c. comparisons of DNA and amino acid sequences
d. Comparative anatomy
9. Within a few weeks of treatment with the drug 3TC, a patient’s HIV population consists entirely
of 3TC-resistant viruses. How can this result best be explained?
a. HIV has the ability to change its surface proteins and resist vaccines.
b. The patient must have become reinfected with 3TC-resistant viruses.
c. HIV began making drug resistant versions of reverse transcriptase in response to the drug.
d. A few drug-resistant viruses were present at the start of treatment, and natural selection
increased their frequency.
e. Some viruses developed drug resistance and then passed their resistant genes to all the
patient’s viruses.
Short Answer
Read the questions carefully and answer in the space provided.
Communication
1. In everyday English, the word adaptation means an adjustment to environmental
conditions. How is the evolutionary definition of adaptation different from the everyday
English sense? (2 marks)
2. Evolutionary relationships among groups of organisms are often reflected through the use
of different types of evidence to determine how closely related different organisms are.
a) Identify and describe (with examples) three different kinds of evidence used to determine
the relatedness of different species to one another. [6 marks]
b) Explain how the evolution of jaws in animals was a tremendous advantage to those
organisms. [2 marks]
Inquiry
4. Describe how the investigations of each of the following may be used to either support or
discredit the theory of evolution by natural selection. [4 marks]
A: Fossil record
B: Molecular record
5. Suppose that you are starting a long-term study of a population of annual, flowering plants
isolated on a small island. Reading some recent papers has convinced you that global warming is
real and will lead to significant, long-term changes in the amount of rain the island receives.
a) Outline the observations and experiments you would need to do in order to document
whether natural selection occurs in your study population over the course of your
research. (4 marks)
b) What traits would you measure, and why? (4 marks)
Application
7. There is a population of 500 individuals consisting of grade 11 biology students. 30
individuals have a disease named “talkativia” (tt) which uncontrollable acts on their muscles
in their mouth and vocal cords to cause involuntary reactions, thus causing massive amounts
of noise coming out of their mouths. 400 individuals are homozygous dominant, thus do not
carry the gene for talkativia. Calculate the frequency of the genotypes and alleles in this
population.
8. During a drought on the island Daphne Major in 1977, a population of finches ate most of
the small, soft seeds on the island leaving only large hard seeds. Only birds with large beaks
could eat the larger hard seeds, while birds with smaller beaks were forced to scratch the soil
and turn over stones in search of remaining smaller seeds. Examine the following figures (1
and 2) on the next two pages.
(Figures from or adapted from Freeman, S. and Herron, J.C. (2004) Evolutionary Analysis.
Upper Saddle River: Prentice-Hall)
Figure 1: Distribution of beak size before and after the drought.
a) Darwin’s first postulate states that there must be variation among individuals of a
population. What would figure 1 look like if there was no variation in the population? (1
mark)
Figure 2: Beak sizes of finches hatched before and after the 1977 drought.
b) Darwin’s second postulate is that some variation is heritable. What would figure 2 look
like if beak depth showed variation, but the variation was not heritable? (2 marks)
c) Did this population of finches evolve? Explain. (4 marks)