Deck 4: Genes and Their Evolution: Population Genetics

Question 1

Which of the following is NOT a genetic disorder that decreases susceptibility to malaria?

A) G6PD deficiency (favism)
B) sickle-cell anemia
C) Huntington's chorea
D) thalassemia

Answer 1

Huntington's chorea

Question 2

When individuals of the same species are reproductively isolated, genetic differences may accumulate in sufficient number so that new species could emerge.Such an event would be an example of

A) microevolution.
B) the founder effect.
C) equilibrium.
D) macroevolution.

Answer 2

macroevolution.

Question 3

What is the meaning of the phrase "disease is an agent of natural selection"?

A) Disease can favor survival of individuals who carry specific alleles.
B) Natural selection can cause a disease.
C) Disease removes the effects of natural selection.
D) Disease randomizes natural selection.

Answer 3

Disease can favor survival of individuals who carry specific alleles.

Question 4

Together, all of the alleles contained within a group of interbreeding individuals are known as a

A) gene pool.
B) population.
C) clinal distribution.
D) polymorphism.

Question 5

Australian aborigines are an endogamous society.This means that marriage and reproduction take place within the group, leading to

A) increased genetic diversity through genetic drift.
B) migration without gene flow.
C) more genetic diversity than would be observed in an exogamous society.
D) decreased genetic diversity due to a lack of admixture.

Question 6

The physical location of a gene within the genome is called the

A) chromosome.
B) nucleus.
C) address.
D) locus.

Question 7

Hardy-Weinberg equilibrium assumes

A) strong selection pressure on the trait(s) being studied.
B) a significant mutation rate from generation to generation.
C) gene flow that is equal both into and out of the population.
D) no gene flow, mutation, or natural selection.

Question 8

Evolution can best be defined as

A) the appearance of a new species.
B) a change in allele frequencies in a breeding population over time.
C) changes in the DNA of an individual over his or her lifetime.
D) a process that occurs only over extremely long periods of time.

Question 9

Which of the evolutionary forces is MOST likely to decrease variation between populations?

A) gene flow
B) the founder effect
C) mutation
D) natural selection

Question 10

Mutations in DNA found in which cells are MOST likely to have significant evolutionary consequences?

A) sex cells (gametes)
B) red blood cells
C) skin pigment cells
D) brain cells

Question 11

In certain species of nonhuman primates there are groups where only one dominant female has access to mates.The other females must wait until the opportunity to mate presents itself.This
Will have direct impacts on "fitness," influencing which of the following?

A) reproductive success
B) aggressiveness
C) strength
D) age at death

Question 12

The ABO and MN blood-type frequencies of the Dunkers differ significantly from those of current American and German populations due to

A) genetic drift.
B) natural selection.
C) gene flow.
D) mutation.

Question 13

How can humans become infected with malaria?

A) having the parasite enter the blood while being fed on by infected mosquitoes
B) having a genetic mutation that manifests as the disease
C) drinking bad water
D) eating spoiled food

Question 14

Another name for the evolutionary force called gene flow is

A) the founder effect.
B) disruptive selection.
C) admixture.
D) transposition.

Question 15

The type of selection that favored progressively larger brain size in human evolution is ________ selection.

A) natural
B) directional
C) stabilizing
D) disruptive

Question 16

A deme is

A) the nongenetic part of inheritance, including learned behavior.
B) all the members of a species.
C) the part of a gene pool that does not reproduce.
D) a group of organisms that have the potential to reproduce.

Question 17

A point mutation that does NOT result in a change to the amino acid coded for is said to be a ________ mutation.

A) spontaneous
B) synonymous
C) selective
D) stabilizing

Question 18

The clinal decrease in type B blood from East Asia to western Europe is probably the result of

A) the founder effect.
B) stabilizing selection.
C) mutation.
D) gene flow.

Question 19

The southern migration of which African people may have led to a significant increase in the incidence of malaria?

A) Masai
B) Turkana
C) Efe
D) Bantu

Question 20

While conducting research with a small population in South America you note that an overwhelming majority of individuals exhibit signs of a specific genetic abnormality.This is MOST likely the result of

A) natural selection.
B) the founder effect.
C) extinction.
D) gene flow.

Question 21

Spontaneous mutation is the result of

A) unknown causes.
B) X-rays.
C) toxic chemicals.
D) UV radiation.

Question 22

What effect does natural selection have on population variation?

A) It increases variation.
B) It decreases variation.
C) It both increases and decreases variation.
D) It does not affect variation.

Question 23

A genetic study conducted over multiple generations found that the frequency of genotypes in the first generation were AA: 0.36, Aa: 0.48, and aa: 0.16.In the second generation, genotype frequencies shifted to AA: 0.16, Aa: 0.48, and aa: 0.36.According to the Hardy-Weinberg equilibrium, we can assume

A) random mating has altered gene frequencies.
B) gene flow has possibly shifted the gene frequencies.
C) mating in this population must be nonrandom mating.
D) gene flow has possibly shifted the gene frequencies AND mating in this population must be nonrandom mating.

Question 24

Patrilocal societies are expected to display

A) greater mtDNA diversity than Y chromosome diversity.
B) roughly equivalent mtDNA and Y chromosome diversity.
C) greater Y chromosome diversity than mtDNA diversity.
D) no strong correlation between societal structure and genetic diversity.

Question 25

The mutation known as trisomy 21, in which an extra copy of chromosome 21 is present, is more commonly known as ________ syndrome.

A) Turner
B) Down
C) Klinefelter's
D) Williams

Question 26

Transposable elements are DNA sequences that

A) are not coded to produce proteins.
B) contain numerous point mutations.
C) occur only on the X and Y chromosomes.
D) can copy themselves into entirely new areas of the chromosomes.

Question 27

Frameshift mutations are more likely to have an impact at the phenotypic level because they

A) are the result of a change in a single nucleotide.
B) are the result of exposure to radiation.
C) produce a protein having no function.
D) are mobile pieces of DNA.

Question 28

Over a period of two generations, the frequency of green dung beetles in a population shifts from 75% to 71%, while the frequency of brown dung beetles within this population shifts from 25% to 29%.This is an example of

A) minievolution.
B) microevolution.
C) millievolution.
D) nanoevolution.

Question 29

A genetic study conducted over two generations found that the frequencies of genotypes in the first generation were AA: 0.36, Aa: 0.48, and aa: 0.16.In the second generation, genotype frequencies remained the same.According to the Hardy-Weinberg equilibrium, we can assume

A) negative assortative mating has maintained gene frequencies.
B) mutations have likely occurred, resulting in the same frequency.
C) mating in this population is random.
D) the population is small and we cannot detect change.

Question 30

Why is the incidence of sickle-cell anemia an excellent example of a "balanced polymorphism,"
in which two or more alleles are maintained by natural selection in a population?

Question 31

You are reading a scientific article about cheetahs that have stripes instead of spots.The article refers to this as a genetic mutation.Though they have no negative impact on the cheetahs' fitness, why are the stripes nevertheless considered a genetic mutation?

A) Mutations are often adaptively neutral.
B) Mutations always emerge as evolutionary disadvantages eventually.
C) Mutations never have an effect on the phenotype.
D) Mutations only affect genotypes.

Question 32

Familial hypercholesterolemia, an autosomal dominant disease, is five times more frequent in the Afrikaner population of South Africa than in the original population of Europe from which the ancestors to the Afrikaners emigrated.This represents an example of

A) natural selection.
B) bottleneck.
C) the founder effect.
D) kin selection.

Question 33

The best-documented case of industrial melanism involves

A) Galápagos finches.
B) dung beetles.
C) monarch butterflies.
D) peppered moths.

Question 34

Fitness trade-off refers to selection favoring which genotype?

A) homozygous dominant
B) homozygous recessive
C) heterozygous
D) No genotype is favored.

Question 35

In a classroom taste test for PTC the genotype frequency was determined to be P = 0.35 and Q = 0.65.After applying the Hardy-Weinberg equation, the percentage of genotypes was found to be as follows:

A) p² = 0.12; 2pq = 0.46; q² = 0.42.
B) p² = 0.35; 2pq = 0.00; q² = 0.65.
C) p² = 0.12; 2pq = 0.65; q² = 0.23.
D) p²= 0.20; 2pq = 0.20; q² = 0.60.

Question 36

The absence of the A and B blood type alleles in Native American populations is a result of

A) natural selection.
B) gene flow.
C) the founder effect.
D) mutation.

Question 37

The evolution of the modern horse with a single hoof on each limb from a dog-sized ancestral species with multiple digits is an example of

A) macroevolution.
B) stabilizing selection.
C) disruptive selection.
D) microevolution.

Question 38

An individual who displays the disease sickle-cell anemia must have inherited the deleterious allele from both phenotypically normal parents.This individual is therefore

A) homozygous, with two dominant alleles.
B) homozygous, with two recessive alleles.
C) heterozygous, with one dominant and one recessive allele.
D) haplozygous.

Question 39

A random change in allele frequencies over time is known as

A) genetic drift.
B) gene flow.
C) admixture.
D) gene migration.

Question 40

Which of the following is a good definition of natural selection?

A) survival of the fittest
B) nonrandom elimination of alleles
C) upward progression
D) random changes in organisms' genetic makeup

Question 41

What is a polymorphic trait? Provide two examples of polymorphic traits in modern humans, and give one example of a monomorphic trait.

Question 42

Explain how the founder effect can lead to a descendent population that differs greatly from its parent population over a relatively short period of time.

Question 43

Why is the peppered moth an excellent example of directional selection?

Question 44

Why is a frameshift mutation far more likely to lead to a defective protein than a point mutation?