EXAMPLE EXAM QUESTIONS
UNIT IV: EVOLUTION
1. You carefully study populations of two very similar meadow mice, one from the northeast U.S. and one from Texas You want to know whether the populations belong to the same species or to two different species You could most confidently decide this if you could:
a. show that the ranges of the two mice overlap without hybridization occurring.
b. bring the two types of mice into the laboratory to see if they will mate.
c. demonstrate that the natural ranges of the two types of mice are entirely allopatric.
d. show that there are statistically significant color differences between the two types.
e. show that the northeastern mice live in wetter habitats than the Texan mice.
a. is a process by which populations of one species diverge genetically and producing one or more new species.
b. is the result of minor extinction events.
c. only results from interspecific hybridization.
d. is completed when two different species are able to interbreed.
e. always takes millions of years.
3. Which of the following contributed to the success of Charles Darwin?
a. documentation of his ideas by prodigious amounts of writing and based on many observations.
b. unusual circumstances or "trifling chances."
c. abundance of curiosity about he natural world.
d. independently wealthy family.
e. all of the above.
4. What of the following is NOT true about mutations?
a. Mutations are base substitutions in the DNA code.
b. Mutations can be caused by radiation.
c. Since most mutations are harmful, they cannot be the basis for improvement of fitness of individuals of a population.
d. Some mutations are lethal.
e. Many mutations are neutral, and therefore neither harm nor help the individual that possesses them.
5. Two individuals are unquestionably members of the same species if they:
a. possess the same number of chromosomes.
b. breed at the same time.
c. are phenotypically indistinguishable.
d. can mate and produce fertile offspring in captivity.
e. pass the text of sympatry.
6. The "Founder Principle" is illustrated by:
a. the evolution of an adaptation in several grass species in response to high concentration of heavy metals in mine tailings.
b. shift from light to dark colored Peppered Moths.
c. the presence of apparently non-adaptive phenotypic characters in island populations of certain plants.
d. the appearance of a few North American continental birds in Hawaii
e. maintenance of human blood types
7. New combinations of genes may be produced by:
c. crossing over
d. sexual reproduction
e. all of the above
8. Reproductive isolation mechanism is BEST defined as
a. males competing for females.
b. the process by which certain individuals are. selected for mating more frequently.
c. a blockage of gene flow between populations (no successful mating occurs.
d. the inability of a hybrid to reproduce.
e. all of the above.
9. Which of the following is NOT a weakness in Darwin's Theory of Evolution?
a. A basic mechanism for speciation was unknown by Darwin.
b. There were many unexplained gaps in the fossil record.
c. Darwin observed that variation existed among individuals of a species.
d. Darwin observed a lack of countless transitional forms between species.
e. Darwin could not explain the formation of such complicated structures (as the vertebrate eye.
10. Various theories of evolution:
a. can never be falsified, thus evolutionary biology is not a science.
b. have been falsified, but others have been tested and supported by the evidence thus may never be falsified.
c. include the theory of natural selection which is clearly supported by the evidence.
d. includes the falsified theory of mutationism.
e. all of the above except a
11. Gaps in the fossil record:
a. clearly refute the modern synthetic theory of evolution
b. seem to support the theory of evolution when the founder principle appears to be one of the most frequent means by which new species evolve
c. clearly refutes the creationists theory of instant origin of separate and distinct species
d. would be caused by small isolated rapidly evolving populations
e. b and d above
12. Ensatina is a salamander that
a. is now in the process of speciation, forming perhaps several new species
b. clearly proves the concept of punctuated equilibrium
c. clearly evolved from a single founders population
d. illustrates stabilizing selection
e. none of the above
13. The theory of natural selection postulates that:
a. in each generation, individuals well adapted for their environment are more likely to live longer and tend to produce more progeny than the less well adapted individuals
b. the death of individuals occur completely at random with respect to their genotypes
c. the death of individuals occur completely at random with respect to their phenotypes
d. the survival and reproductive success of individuals depend to a limited extent upon their genetic adaptations to their environment e. most deaths of individual organisms occur soon after fertilization, as a result of hereditary deficiencies
14. Which of the following demonstrates a clear reproductive isolation between two populations?
a. allopatric distribution.
b. a blockage of gene flow between two sympatric populations.
c. sympatric distribution with considerable gene flow between the two populations.
d. the inability of a species to continue to reproduce.
e. the occurrence of considerable crossing over during meiosis.
15. The fossil record in poor because:
a. very few organisms were preserved as fossils.
b. organisms tend to decay before coming a fossil.
c. animals with hard parts are preserved more easily.
d. geological processes may destroy fossils.
e. all of the above.
16. Complete reproductive isolation is evidence for:
e. gene flow.
17. Adaptive radiation:
a. is another term for natural background radiation that causes
b. is the evolution of the biggest and fiercest animals
c. is the formation of new adaptive structures or colors within a species
d. is the evolution of many species that occupy many different niches, from a single ancestral form
e. is the development of "radiant" fin structures on fishes, or development of fin like structures on dinosaurs
18. When a bell shapes curve results from the analysis of some variable in a population, the type of natural selection that is probably occurring in the population with regard to that variable is:
19. Four of the five answers listed below are characteristic of mutations Select the exception
b. lethal, beneficial or neutral
d. effects depend upon environment
20. The fossilized remains of extinct organisms
a. provides critical evidence that life has evolved over time.
b. provide a complete record of evolutionary history.
c. demonstrate that nature never "takes leaps" in evolution.
d. is a frequent, common event.
e. all of the above are true.
21. The number of different alleles per gene in a natural population is most frequently:
c. many more than two
d. greater than two, but never greater than ten
e. none of the above
22. When two species occupy similar niches and compete for some resource that is in short supply
a. one of the species may become extinct.
b. character displacement may occur resulting in lower competition.
c. both species will always become extinct.
d. the two species usually cooperate in nature, and share the resources equally.
e. two of the above are correct.
23. Gene flow is best defined as:
a. the movement of genetic material from the nucleus to the cytoplasm
b. the transmission of genetic information from the cytoplasm to the nucleus
c. the transmission of genetic information from the parents to the offspring
d. the spread of alleles through a population over a period of successive generations
e. the movement of genes from one chromosomes to another
24. Which is NOT an example of an isolating mechanism?
a. species-specific courtship rituals
b. Hardy-Weinberg equilibrium
c. incompatable gametes
d. infertile hybrids
e. all of the above are isolating mechanisms
25. Natural selection can best be defined as:
a. the best-adapted individuals live to a very old age
b. differential reproduction
c. differential population-growth rates
d. enhanced survival of those individuals with favorable acquired phenotypic traits
e. the elimination of the weak by the strong
26. Which of the following BEST describes pre-Darwinian thought?
a. Each species is a distinct and unchanging entity.
b. About 99.9% of the species that have lived are now extinct.
c. There is an extraordinary diversity of extinct species that once lived on the earth.
d. Evolution occurred by transmutation.
e. Species adapt to pressure from the environment.
27. Which of the following is NOT correct with respect to natural selection and adaptation?
a. In a few generations, a population being subjected to natural selection should reach adaptive perfection
b. Since predators also evolve, their prey can never evolve perfect adaptations
c. The process of natural selection tends to remove the less fit, but sometimes even the least fit will survive and produce offspring
d. Natural selection acts on prey but never predators.
e. Two of the above choices are correct
28. The influence of genetic drift on allele frequencies increases as:
a. gene flow increases.
b. population size decreases.
c. mutation rate decreases.
d. the number of heterozygous loci increases.
e. all of the above.
29. The primary evolutionary unit is the:
c. germ cell
30. Genetic variation
a. is due to random processes only
b. occurs because the organism needs that variation in order to survive
c. occurs because an organism wants that type of variation
d. can occur for any of the above reasons as long as the organism benefits
e. is a result of both random events and natural selection