Multiple Choice
1. In a random breeding population of a small mammal, the gene for coat colour has two alleles: G, which is dominant producing a grey coat, and g, which is recessive producing a white coat. The white individuals are selected against by hawk predation such that each individual has a 10% probability of surviving to a reproductive age, while the grey animals have a 75% probability. Which of the following statements will best describe the population for these alleles after 100 generations of continued random breeding?
A. The G allele will now be the only allele present in the population.
B. The g allele will now be the only allele present in the population.
C. Both alleles will be present in equal numbers.
D. The G allele will be the allele with the highest frequency and the g allele will still be present.
2. The production of new genes or changes in allelic forms is the result of
A. gene flow
B. genetic drift
C. mutation
D. adaptation
3. The major evolutionary force that causes changes in gene frequencies is
A. Hardy-Weinberg principle
B. natural selection
C. directional selection
D. bottleneck effect 4. Hamadryas baboons are found in Saudi Arabia. At some point in their lives, female Hamadryas baboons leave their birth group and migrate to a different one. This helps all populations maintain healthy and diverse gene pools and may help them to survive.
The above is an example of:
A. stabilizing selection
B. gene flow
C. coevolution gene flow
D. non random mating
5. Hardy-Weinberg equilibrium
A. rarely occurs in nature because most populations are evolving
B. never occurs in nature because it is a principle to be applied to hypothetical situations
C. occurs only in strictly controlled laboratory situations
D. will occur if the population is small and breeds randomly
6. Speciation can result from
A. reproductive isolation
B. geographic isolation
C. disruptive selection
D. all of the above
Asparagus, a green vegetable, has one notorious side effect for some diners who eat enough of it. Within a half-hour of asparagus consumption, some people notice their urine has acquired a very pungent odor, often compared to rotting cabbage or rotten eggs. The effects of asparagus on urine is harmless, but unpleasant. Scientists believe that those with a certain gene produce a digestive enzyme which breaks down the asparagus into a chemical compound methyl mercaptan, which is the same chemical which gives a skunk its defensive smell. Methyl mercaptan, eventually goes through the kidneys and is excreted as a waste product in the urine. Asparagus does not affect everyone, however. Only those with a certain gene can break down the chemicals inside the asparagus into their smelly components, and only those with the proper gene can smell the results of that chemical breakdown.
7. If the allele for the enzyme that breaks down methyl mercaptan is dominant and 73% of a population have this enzyme, what percentage of the population would be expected to be heterozygote for this enzyme?
A. 27% B 39%
C. 50%
D. 24%
8. What is the difference between a population and a gene pool?
A. There is no difference.
B. The population remains constant but the gene pool changes.
C. A population is comprised of the same species and a gene pool is comprised of all their genes.
D. Populations are less important to evolution than are gene pools.
9. The equation
A. the process of evolution
B. the size of a population
C. the natural selection law
D. the makeup of a gene pool
describes
Use the following diagram to answer the next two questions.
10. The homozygous dominant individuals constitute what proportion of the population?
A. 0.6%
B. 52%
C. 36%
D. 24%
11. What proportion of the gametes in this population contain gene c?
A. 0.16%
B. 24%
C. 40%
D. 48% 12. In a population in which 1% has sickle-cell anemia, what percentage of the population are carriers for the trait?
A. 81%
B. 1%
C. 18%
D. 99%
13. A scientist determines that 9% of a human population is albino resulting from recessive genes for skin pigmentation. What is the frequency of the recessive allele in this population?
A. 1.0
B. 0.1
C. 0.03
D. 0.3
14.
Northern elephant seals have reduced genetic variation because of the intense hunting that humans inflicted on them in the 1890s. Hunting reduced their population size to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000—but their genes still carry the marks of this; they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted.
The above is an example of:
A. bottleneck effect
B. genetic drift
C. gene flow D. heterozygote advantage 15. Once speciation has occurred ( see notes in course folder)
A. gene flow ceases
B. reproductive isolation exists
C. two species exist
D. all of the above
16. Evolution by natural selection would be least in a population
A. that is on the verge of extinction
B. with no predators or competitors
C. with large phenotypic variations
D. that has a stable number of members
17. Two populations of field mice become separated by a new highway so that the gene flow is now impossible. After ten years a researcher detects that evolutionary change has occurred in the populations. Mice found on the east side of the highway have a higher percentage of individuals with longer and darker whiskers than the population found on the west side of the highway. The two habitats are identical. What is the most probable reason for the difference?
A. Natural selection has occurred in each group.
B. Nonrandom mating has occurred.
C. Mutations have occurred in each group.
D. Genetic drift has occurred in each group.
18. The most effective means of conservation is to
A. remove predators
B. preserve habitats
C. vaccinate against disease
D. census the species during breeding season
19. The HHC mutation in DNA is encoded in mRNA by the process of
A. translation in the nucleus
B. translation on the ribosome
C. transcription in the nucleus
D. transcription on the ribosome 20. The frequency of the dominant allele associated with HHC in the Caucasian population of the United States IS
A. 0.005
B. 0.071
C. 0.864
D. 0.929
21. Individuals who have sickle cell anemia are homozygous for the defective allele HbS . The normal allele is HbA . What is the frequency of the Hb A allele in the human gene pool in western Africa?
A. 0.72
B. 0.85
C. 0.90
D. 0.95
22. Which of the following conclusions can be drawn from all the information provided on sickle cell anemia? Read p. 594-595 of text.
A. The sickle cell gene will eventually disappear because of its interaction with malaria.
B. Malaria causes heterozygous individuals to be less fertile than us individuals.
C. In Africa,sickle cell anemia will disappear since it is lethal in the homozygous condition.
D. In Africa, carriers for sickle cell anemia have an advantage over homozygous individuals. 23. The technology of transferring a gene from a bacterium into a green plant is based on the principle that
A. all genes carry the same genetic information
B. all genes have the same basic chemical components
C. the genotypes of the bacterium and green plant are the same
D. the phenotype of an organism is not altered when one gene is exchanged for another
24. The “founder effect” seems to occur when
A. the environment favours one population over another population
B. a non-representative subpopulation forms the basis for an isolated population
C. individuals from one population move into and become part of a second population
D. two similar populations exist in the same community without being reduced in number 25. The frequency of the gene that controls the production of schreckstoff by minnows is likely
A. to increase in the gene pool of the population
B. to decrease in the gene pool of the population
C. to stay the same in the gene pool of the population because natural selection is occurring
D. to stay the same in the gene pool of the population because natural selection is not occurring
Written Response (12 Marks) 1. a. Explain how a gene mutation could alter the diaphorase enzyme’s amino acid sequence. (2marks)
b. Determine the frequency of the recessive allele for the Fugate family during this time. Show your work. (2marks)
c. Predict the theoretical percentage of individuals in the Fugate family that were heterozygotes during this time. Show your work. (2marks)
d. Explain why the frequency of the blue skin phenotype was higher in the Fugate family than in the general American population. (1mark)
e. Identify two ways in which the population, which consisted of six generations of the Fugate family, did not meet the conditions for Hardy–Weinberg equilibrium. (2marks) f. Although he was very blue at birth , within his first few weeks, Benjy’s skin colour changed to normal with no treatment required. At the age of seven, other than purplish blue lips when he was cold or angry, Benjy’s colouration was normal.
i. What is Benjy’s genotype? (1mark)
ii. Give a possible explanation for the change in Benjy’s phenotype overtime. (1mark)
iii. Individuals with hereditary methemoglobinemia can be treated easily with methylene blue pills. Methylene blue acts as an “electron donor” converting methemoglobin to hemoglobin, which results in pink skin colouration.
Explain why treated blue people can still produce offspring with hereditary methemoglobinemia. (1mark