Deck 4: Genes and Their Evolution: Population Genetics

Question 1

Population geneticists refer to a reproductive population as a deme.

Answer 1

True

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)founder effect.
C)equilibrium.
D)macroevolution.

Answer 2

macroevolution.

Question 3

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)founder effect.
C)extinction.
D)gene flow.

Answer 3

founder effect.

Question 4

Klinefelter's syndrome results from males passing on an extra copy of the X chromosome (resulting in a 47-chromosome,XXY karyotype).

Question 5

The inability to taste PTC indicates a homozygous recessive genotype.

Question 6

Malaria is caused by:

A)bites from infected mosquitoes.
B)a genetic mutation.
C)drinking bad water.
D)eating spoiled food.

Question 7

Reproductive isolation is key to the development of individual species.

Question 8

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 gain mate access 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 9

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

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

Question 10

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 11

Mutations caused by some external agent such as X-rays or exposure to toxic chemicals are called spontaneous mutations.

Question 12

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,genetic drift,or natural selection.

Question 13

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 14

Mutation is one of many sources of new alleles.

Question 15

The effects of gene flow have decreased from 10,000 years ago to the present.

Question 16

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

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

Question 17

Genetic drift is the force of evolution that is most powerful when acting on very large populations.

Question 18

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

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

Question 19

Lactase persistence occurs in human populations with a long history of animal husbandry and milk consumption.

Question 20

Sickle-cell anemia is the result of a single-point mutation on chromosome 11.

Question 21

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 22

The best-documented case of industrial melanism involves:

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

Question 23

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 24

What effect does natural selection have on population variation?

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

Question 25

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 26

Mutations to 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 27

The vector for transmitting the malarial parasite to humans is:

A)dirty drinking water.
B)mosquitoes.
C)rats.
D)monkeys.

Question 28

Spontaneous mutation is the result of:

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

Question 29

We know that Upper Paleolithic food foragers in Europe are ancestors to modern European populations because of:

A)recent genetic research.
B)archaeological evidence.
C)both populations living in the same area.
D)none of the above

Question 30

Studies of Darwin's finches have found that at certain points in time all finches on the island have either wide beaks or sharp narrow beaks.The type of evolution that leads to this phenotype distribution is:

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

Question 31

A point mutation that does not result in a change to the amino acid coded for is said to be a:

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

Question 32

Another name for the evolutionary force called gene flow is:

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

Question 33

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)insert themselves into other parts of the genome.

Question 34

You are reading a scientific article about cheetahs that have stripes instead of spots.The article refers to this as a genetic mutation.Though you see it has no negative impacts on the cheetahs' fitness,the stripes are nevertheless considered a genetic mutation because:

A)mutations can result in an evolutionary advantage.
B)mutations can result in an evolutionary disadvantage.
C)mutations can have no effect on the phenotype.
D)all of the above

Question 35

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

Question 36

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

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

Question 37

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

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

Question 38

A random change in allele frequencies over time is known as:

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

Question 39

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)There is no strong correlation between societal structure and genetic diversity (none of the above).

Question 40

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

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

Question 41

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

Question 42

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

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

Question 43

Fitness trade-off refers to selection favoring which genotype?

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

Question 44

A genetic study conducted over two generations found that the frequency of genotypes in the first generation were,AA: 0.36,Aa: 0.48,aa: 0.16.In the second generation,genotype frequencies remained the same.According to 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 45

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 46

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 47

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 dominant.
B)homozygous recessive.
C)heterozygous.
D)haplozygous.

Question 48

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

Question 49

A genetic study conducted over multiple generations found that the frequency of genotypes in the first generation were,AA: 0.36,Aa: 0.48,aa: 0.16.In the second generation,genotype frequencies shifted to AA: 0.16,Aa: 0.48,aa: 0.36.According to 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)both B and C

Question 50

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

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

Question 51

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

Question 52

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

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

Question 53

In a classroom taste-test for PTC the genotype frequency was determined to be P = .35 and Q = .65.After applying the Hardy-Weinberg equation,the percentage of genotypes were found to be as follows:

A)
B)
C)
D)none of the above

Question 54

Familial hypercholesterolemia,an autosomal dominant disease,is five times more frequent in the Afrikaaner population of South Africa than in the population of Europe or the United States.This represents an example of:

A)natural selection.
B)bottle neck.
C)founder effect.
D)kin selection.

Question 55

A study of Darwin's finches after a long period of drought found that all species of finch on one of the islands have developed wide beaks in order to break open seeds.The type of evolution that leads to this phenotype distribution is:

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