Deck 17: Genes Within Populations

Question 1

When bird populations migrate and mix with populations that do not migrate this can cause

A) gene blending.
B) mutation.
C) gene flow.
D) genetic drift.

Answer 1

gene flow.

Question 2

Darwin proposed that natural selection occurs in an environment by

A) favoring those individuals with the most favorable acquired characteristics.
B) producing a constant number of offspring while in that environment.
C) surviving for a fixed amount of time.
D) resisting the environment and keeping the environment from changing.
E) favoring heritable features that make the organism better suited to survive and reproduce.

Answer 2

favoring heritable features that make the organism better suited to survive and reproduce.

Question 3

There are more than 30 blood group genes in humans, in addition to the ABO locus. If an additional set of previously unknown blood group genes were used to determine blood groups, this would effectively increase ________ in human populations.

A) genetic variability
B) homozygosity
C) selective mating
D) gene flow
E) founder effects

Answer 3

genetic variability

Question 4

Female cardinals select male mates in part based on their bright red color. What effect would this have on a cardinal population that was in Hardy-Weinberg equilibrium?

A) The red allele frequencies would remain unchanged because of equilibrium.
B) The frequency of red alleles would be greater than those predicted by Hardy-Weinberg equilibrium.
C) The red allele frequencies would decrease because of equilibrium.
D) The frequency of red alleles would be less than those predicted by Hardy-Weinberg equilibrium.
E) The frequency of red alleles would be equal to those predicted by Hardy-Weinberg equilibrium.

Question 5

Large ears is a rare trait in a mainland population of mice. A female mouse homozygous for very large ears sneaks onto a boat and arrives at an island that already contains mice. This mixing will lead to a population with a higher incidence of big ears than the mainland population because of

A) natural selection.
B) increased mutation.
C) genetic drift.
D) a bottleneck effect.
E) gene flow.

Question 6

An island is on the migration route of sea birds. What best describes the way this will change Hardy-Weinberg equilibrium in non-migrating populations, if the migrating birds have very different allelic frequencies?

A) Mutations will shift the allele frequency of the island sea birds and alter their phenotype.
B) Equilibrium will be changed due to the genetic nonrandom mating occurring introducing new alleles.
C) Equilibrium may be altered nearer to a 0.5 frequency and therefore alter the allelic structure of the island birds.
D) Natural selection will become stronger in the tree nesting birds.
E) The 0.5 equilibrium will be greatly altered due to influencing frequencies from migrating birds.

Question 7

The disease sickle-cell anemia is common in malaria-infested areas because individuals that are heterozygous for the gene (AS) have enhanced resistance to malaria over normal individuals (AA). Individuals with severe sickle-cell anemia (SS) usually die before reproduction. If this population moves to an area without malaria, what will happen to the allele frequency of the A allele over time?

A) It will go down because there is no malaria.
B) It will go down because there is no sickle cell anemia.
C) It will go up because there is no sickle cell anemia.
D) It will go up because there is no malaria.

Question 8

A population of lizards lives in a rocky area next to a desert. Some lizards are light colored and blend into the sand, whereas others are dark and blend into the rocks. Over time, this lizard population is likely to

A) remain one species as a result of directional selection.
B) evolve into two separate species as a result of disruptive selection.
C) remain one species as a result of disruptive selection.
D) evolve into two separate species as a result of directional selection.
E) remain one species as a result of stabilizing selection.

Question 9

A selection experiment you are doing requires certain conditions in order for evolutionary change to occur. What conditions would cause this change?

A) Variation between individuals in a population.
B) Genetic variations being heritable.
C) No variation existing between individuals in the next generation.
D) Survival rate of offspring varying due to parental genetic differences.

Question 10

In the lab you show that guppies under different predatory conditions change in rapid evolution. In the field you wish to design an experiment that would generate data to support your observation. What experiment would best help you achieve your goal?

A) Transfer wild guppies from a predator free pond into one with predators but no guppies, over time observe the guppies for physiological changes.
B) Use the guppies from the lab and introduce them into a predator rich pond free of wild populations of guppies, observe trait changes.
C) Place predators from the lab into a pond free of other predators but with wild populations of guppies and monitor changes in physical traits.
D) Create a mixed population of wild guppies and place them into a controlled environment with predators to record the genetic changes.

Question 11

In both field and lab studies of guppies, you observe a rapid evolutionary change in the physiological traits that help the animals avoid predation. This observation illustrates which main point?

A) Allele frequency is maintained in all conditions.
B) Natural selection is an ongoing process.
C) Dominant genes will always increase survival rates.
D) Evolutionary change is facilitated by natural selection.

Question 12

You are studying a population of isolated mammals. There is a great deal of variation within the population for specific traits that strengthen survivorship in an ever-changing environment. This represents which type of selection?

A) Frequency-dependent selection
B) General selection
C) Heterozygous selection
D) Gene flow selection

Question 13

Hardy-Weinberg states out that original genotype proportions within a population remain constant across generations if certain assumptions were met. These assumptions include

A) the occurance of random mating.
B) the lack of selection.
C) the absence of polymorphic loci in the population.
D) a large population size.
E) an absence of gene flow.

Question 14

Mutations affect Hardy-Weinberg equilibrium by

A) altering frequencies of particular alleles within a population.
B) having a large impact due to low mutation rate.
C) removing variation that affects natural selection.
D) having zero impact on changes in allele frequency.