Midterm II Practise Questions
1. 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
2. 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.
3. The intermediate form of a trait is favored when __________ selection occurs
e. none of these
4. When a population’s allele frequencies are shifting in a consistent direction, ______ selection is occurring
e. none of these
5. Both ends of a range of variation are selected during _________selection
e. any of these
6. Any trait that improves an individual’s fitness is called
a. a degree of fitness.
b. a negative trait
c. a neutral trait.
d. an adaptive trait.
e. none of these.
7. Which of the following is not an observation or inference on which natural selection is based?
a. There is heritable variation among individuals.
b. Poorly adapted individuals never produce offspring
c. Species produce more offspring than the environment can suppo rt.
d. Individuals whose characteristics are best suited to the environment generally leave more offspring than those
whose characteristics are less suited.
e. Only a fraction of the offspring produced by an individual may survive.
8. Natural selection changes all ele frequencies because some _____ survive and reproduce more successfully than
c. Gene pools
9. Sparrows with average -sized wings survive severe storms better than those with longer or shorter wings, illustrating
a. The bottleneck effect Midterm II Practise Questions
b. Stabilizing selection
c. Frequency-dependent selection
d. Neutral variation
e. Disruptive selection
10.Which of the following has the highest Darwinian fitness?
A. A personal trainer who works out at the gym everyday.
B. A scientist who devotes herself t o science & wins the Nobel Prize.
C. A sperm donor who anonymously fathers 52 children.
D. A woman who home schools her two children.
11.Which of the following is the best example of a heritable variation?
A. Skin cancer
C. Red hair
D. Love for music
12. The founder effect is a type of
a. natural selection.
c. genetic drift.
d. gene flow.
12.Natural selection results in organisms perfectly adapted to their environments.
13.Sometimes the most abundant colour form of an animal is preyed upon more extensively than less common forms.
This illustrates the phenomenon of
a. stabilizing selection.
b. directional selection.
c. disruptive selection.
d. frequency-dependent selection.
e. genetic drift.
14.The source of new alleles in a population is
a. natural selection.
e. genetic drift.
15.The Hardy–Weinberg principle of genetic equilibrium tells us what to expect when a sexually
reproducing population is
a. decreasing with each generation.
b. increasing with each generation.
e. not evolving.
16.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
17.What type of variation in a population of finches is passed to the offspring?
A. Any behaviours learned during a finch’s lifetime.
B. Only characteristics that were beneficial during a finch’s lifetime.
C. All characteristics that are genetically determined. Midterm II Practise Questions
D. Any characteristics that were positively influenced by the environment during a finch’s lifetime.
18.The biological species concept is inadequate for grouping
C. Asexual organisms
D. Migratory animals
19.Which of the following biological processes causes adaptation?
C. natural selection
D. genetic drift
20.In what kind of population is random genetic drift most pronounced?
A. Drift is greatest in large populations.
B. Drift is greatest in small populations.
C. Drift is greatest in migrating populations.
D. Drift is greatest in fixed populations.
21.A genetic bottleneck is a good explanation for all but one of the following patterns observed in natural
populations. Which one is not caused by a genet ic bottleneck?
A. achromatopsia on Pingelap Atoll
B. fixed loci in endangered plant populations
C. long, thin necks in giraffes
D. extremely low genetic diversity in cheetahs
22.Why does genetic drift affect small populations more than large populations?
Answer as a short-answer question.
23.What will happen to the size & shape of beaks in medium ground finches, in the future?
A. They will continue to get deeper & wider.
B. They will continue to get deeper, but they should eventually begin to get narrower as well .
C. It depends on changes in the environment.
D. They may fluctuate in size & shape, but they will remain roughly constant over the long term.
24.Which of the following statements is correct?
A. Evolution by natural selection is not progressive. It is random.
B. The largest, strongest & most dominant individuals in a population produce the most offspring.
C. In 1977, individual finches on the Galapagos adapted to drought conditions & passed these traits on to their
D. None of the above statements are correct.
25.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.
26. How can Darwinian fitness most easily estimated?
A. Document how long different individuals in a population survive.
B. Count the number of offspring produced by different individuals in a population.
C. Determine which individuals are strongest.
D. Determine which phenotype is the most common one in a given population.
27. What is an adaptation?
A. A trait