Question 1

Two species of salamanders have overlapping territories and they successfully mate and produce eggs.However,most of the eggs fail to hatch.Only 10% of them hatch,but the tadpoles are weak and are almost all killed by predators.The few tadpoles that exit the water have weak bones and soon die.This is an example of

Accepted Answer

This scenario describes hybrid inviability, as the offspring of the two salamander species are able to mate and produce eggs, but the majority of those eggs fail to hatch and the few tadpoles that do survive have various physical weaknesses that make them unfit for survival. This demonstrates a postzygotic barrier to reproduction.

Question 2

Mating rituals are an example of which type of reproductive isolation?

Accepted Answer

Mating rituals are a type of behavioral isolation, which is a prezygotic barrier that prevents interbreeding between two species due to differences in courtship behaviors or other types of communication.

Question 3

A species of lizard is found on the eastern and western sides of part of a mountain range.On both sides,individual populations are small.On the western side,individual populations are relatively close together and males move extensively among populations to breed.On the eastern side,however,populations are farther apart and males seldom move among more than one or two adjacent populations to breed.If you were to study the genetic diversity of western and eastern populations,which pattern would you expect to find?

Accepted Answer

The limited male movement among eastern populations indicates restricted gene flow, which can lead to decreased genetic diversity within populations. The relatively close proximity of western populations and extensive male movement indicates increased gene flow, which can lead to greater genetic diversity within populations. Therefore, it is reasonable to expect that each western population would be genetically diverse, although the allele frequencies might differ from one population to the next. Eastern populations would be less diverse, and some populations may have only a limited number of the total alleles available in the species. Option D describes this pattern. Option A is incorrect because it suggests that the eastern populations would have fewer different alleles when this is unlikely given the species is present on both sides of the mountain range. Option B is unlikely because it proposes that each western and eastern population would have all of the available alleles, which is rare. Option C is not expected since the eastern populations are expected to have less genetic diversity due to limited gene flow. Option E is incorrect since not all patterns are equally reasonable given the information provided.

Question 4

Frog species mate at different times of the year.This is an example of which type of reproductive isolation?

Accepted Answer

The fact that frog species mate at different times of the year is an example of temporal isolation, as they are reproductively isolated due to differences in the timing of their breeding seasons.

Question 5

From the Hardy-Weinberg equilibrium you can conclude that all populations are evolving.Explain.

Accepted Answer

The answer of From the Hardy-Weinberg equilibrium you can conclude...

Question 6

An extremely harsh winter causes the death of 75% of an endangered antelope population.When considering the future survival of this population,which of the following is a concern for scientists?

Accepted Answer

All of the above are concerns for scientists when considering the future survival of the endangered antelope population. The harsh winter caused a significant reduction in population size, which can increase the chances of genetic drift, reduce allelic diversity, limit gene flow between populations, and increase inbreeding depression among survivors.

Question 7

Which of the following can threaten the ability of a population to adapt to changing environmental conditions?

Accepted Answer

All of the listed choices (bottleneck, founder effect, genetic drift, and inbreeding) can limit genetic diversity within a population, making it more difficult for individuals to adapt to changing environmental conditions. A bottleneck event, for example, reduces the size of a population, which can decrease genetic variation overall. Similarly, the founder effect occurs when a small group of individuals colonize a new area, establishing a new population that may have limited genetic variation compared to the original population. Genetic drift and inbreeding also decrease genetic diversity within a population, making it harder to adapt to changing conditions.

Question 8

Give an example of an organism that lacks mate selection.

Accepted Answer

The answer of Give an example of an organism that...

Question 9

A population of Australian wallabies is found to have many more homozygous individuals than expected.What does this result indicate?

Accepted Answer

The higher number of homozygous individuals suggests that inbreeding is likely occurring in the wallaby population.

Question 10

Zoos often construct extensive genetic profiles of their animals,maintain pedigree books,and trade or share animals for breeding purposes.Why would a zoo with 12 elephants bother to import a male elephant from another zoo,or lend its males to another zoo,often at a huge expense?

Accepted Answer

The answer of Zoos often construct extensive genetic profiles of...

Question 11

What five characteristics must a population have to never have a change in allele frequencies?

Accepted Answer

The answer of What five characteristics must a population have...

Question 12

Reproductive isolation based on location or geography is referred to as

Accepted Answer

Ecological isolation is based on geographical location and differences in habitat, preventing organisms from different areas from interbreeding. Gametic isolation refers to differences in the structure or chemistry of reproductive cells, temporal isolation refers to differences in mating season, behavioral isolation refers to differences in behavior during mating, and mechanical isolation refers to physical differences preventing mating. Therefore, B is the correct choice.

Question 13

An island has a population of 10,000 birds that has 98% gray individuals and 2% black individuals.Generation after generation,this ratio and population size remains basically the same.After a hurricane,10,000 black birds are blown onto the island.What will happen to the population?

Accepted Answer

The answer of An island has a population of 10,000...

Question 14

The biological species concept defines a species as

Accepted Answer

The biological species concept defines a species as a group of organisms that can interbreed and produce fertile offspring. This means that individuals within the same species can mate and produce offspring that are also capable of reproducing, while individuals from different species cannot produce viable offspring. This definition is focused on reproductive isolation as the main factor in defining a species.

Question 15

An island has a population of 100,000 moths that has 98% gray individuals and 2% black individuals.Generation after generation,this ratio and population size remains basically the same.After a hurricane,10,000 black moths are blown onto the island.This is an example of _____________.

Accepted Answer

The answer of An island has a population of 100,000...

Question 16

Why is inbreeding likely to limit the ability of a population to survive?

Accepted Answer

The answer of Why is inbreeding likely to limit the...

Question 17

Incompatibility of mating organs is an example of which type of reproductive isolation?

Accepted Answer

Mechanical isolation occurs when differences in the size and shape of reproductive organs prevent mating between species, making it an example of prezygotic barrier to reproduction.

Question 18

.  Which of the following best describes Hardy-Weinberg equilibrium?

Accepted Answer

Hardy-Weinberg equilibrium represents a population that is not evolving. This means that the population is not experiencing any changes in allele frequencies, is large enough to avoid genetic drift, and does not experience selection, mutation, or migration. Therefore, the population's genetic makeup remains constant from generation to generation, and it is not evolving.

Question 19

What five characteristics must a population have to never have a change in allele frequencies? Are all five of these possible?

Accepted Answer