Question 1

Polyploidy in plants can lead to

Accepted Answer

The answer of Polyploidy in plants can lead to
...

Question 2

The formation of a new species

Accepted Answer

The formation of a new species can occur slowly over millions of years through gradual changes in genetic and physical characteristics, or it can happen rapidly through sudden genetic mutations or changes in reproductive behavior. Therefore, option A is the correct answer. Option B is incorrect as it is possible for speciation to occur in less than a million years. Option C is also incorrect as the formation of a new species is a significant event in evolutionary history. Option D is incorrect as new species have been observed to arise in the natural world.

Question 3

Great controversy exists regarding the "hobbits" of Flores Island. Which of the following arguments would not support the hypothesis that hobbits are the same species as modern humans?

Accepted Answer

The answer of Great controversy exists regarding the "hobbits" of...

Question 4

Polyploidy can lead to

Accepted Answer

Polyploidy typically results in offspring with an odd number of chromosomes, making it difficult or impossible for them to produce viable offspring with individuals with a different number of chromosomes (i.e. reproductive isolation).

Question 5

Populations within a species are connected by

Accepted Answer

Populations within a species are connected by gene flow, which is the transfer of genetic information between populations. This transfer can occur through dispersal of individuals, mating between individuals from different populations, and other mechanisms. Gene flow helps to maintain genetic diversity within a species and can prevent populations from diverging into separate species. Speciation refers to the process of populations diverging into separate species, not the connection between populations within a species. Continental drift refers to the movement of tectonic plates over long periods of time, which can result in changes in the distribution of species. Genetic drift refers to random fluctuations in the frequencies of alleles within a population, which can lead to the loss of genetic diversity over time.

Question 6

In general, geographic isolation occurs when

Accepted Answer

Geographic isolation occurs when populations are separated by a distance that is great enough to limit gene flow. The physical barrier can be a river, mountain range, ocean or any other feature that prevents or reduces the movement of individuals or their gametes between populations. This results in genetic divergence and can lead to the formation of new species over time. Options A, B, and C are incorrect as they do not reflect the primary mechanism or consequence of geographic isolation.

Question 7

The current diversity of dog breeds is due to

Accepted Answer

The current diversity of dog breeds is largely due to artificial selection by humans for certain desired traits such as size, coat color and texture, and temperament, resulting in a wide range of shapes, sizes, and behaviors. Breeders have selectively bred dogs with desired characteristics over many generations, leading to the creation of distinct breeds with specific traits.

Question 8

In the figure below (left), two populations of one species of fruit flies are raised for several generations on different nutrients (starch and maltose). On the right, the members of the two populations were reintroduced and the mating frequencies of flies from the two different populations were recorded. 
Which of the following is true?

Accepted Answer

The observation that male flies are more likely to mate with females from the same nutrient group indicates that the two populations have developed some level of reproductive isolation, but it is not yet complete speciation since some mating still occurs between the two groups. There is no evidence to support options A, C, or D.

Question 9

For two populations to accumulate enough genetic differences to cause speciation, the factors that promote these differences

Accepted Answer

While physical separation can promote speciation, it is not the only factor. Even in populations that are not physically separated, genetic differences can accumulate if the factors promoting those differences have a greater effect than ongoing gene flow. Genetic drift and polyploidy can also play a role, but B is the most accurate and comprehensive choice.

Question 10

Speciation

Accepted Answer

Geographic isolation can lead to speciation by creating reproductive barriers between previously connected populations. This can result in divergent evolution and the formation of new species. B and C are incorrect because speciation is not directed or limited to ring species, and D is incorrect because speciation can actually increase variation by creating new genetic diversity.

Question 11

Geographic isolation limits the _______ between populations of a species.

Accepted Answer

Gene flow refers to the transfer of genetic material between populations, and geographic isolation limits or eliminates this transfer. This can lead to genetic differences and adaptations between populations, and may also result in directional selection over time.

Question 12

Examine the figure below. 
Why have the two plant populations depicted become so different in the time they were separated by the ocean?

Accepted Answer

The plants became different due to the process of adaptation to the different environments on each side of the ocean, ultimately leading to reproductive isolation. This is an example of allopatric speciation. The founder's effect scenario (A) would lead to a loss of genetic diversity in the new population established from a small group, which is not demonstrated in the figure. Increased gene flow between the populations (B) would result in less differentiation between the populations rather than more. The scenario involving rising sea levels (C) leading to the evolution of a new species is not supported by the information in the figure.

Question 13

The improvement of the match between organisms and their environments over time is called ________ evolution.

Accepted Answer

The answer of The improvement of the match between organisms...

Question 14

Which of the following does not provide an example of geographic isolation?

Accepted Answer

Two populations living in different parts of a small lake do not provide an example of geographic isolation as they are not separated by a physical barrier such as a mountain range, valley, or river.

Question 15

Sympatric speciation

Accepted Answer

Sympatric speciation occurs when a new species emerges from a population in the absence of a geographical barrier. This can happen due to factors such as sexual selection, niche differentiation, and chromosomal changes. It is not limited to plants and polyploidy is not always involved.

Question 16

A rainforest is a highly complex habitat, with organisms living at various levels in the trees, on the ground, and underground. Is it possible to consider two populations living in the same tree to be geographically isolated?

Accepted Answer

In a rainforest, a single tree can have multiple microhabitats, allowing populations to be geographically isolated even within the same tree due to lack of interaction.

Question 17

Polyploidy can lead to very rapid speciation in plants because

Accepted Answer

The answer of Polyploidy can lead to very rapid speciation...

Question 18

Which of the following is an example of a prezygotic barrier that can isolate two species living in the same geographic area?

Accepted Answer

Prezygotic barriers occur before fertilization and prevent individuals of different species from mating successfully. In this example, the gametes of one species of orchid are unable to fuse with the gametes of another species of orchid in the same rainforest, preventing successful fertilization and resulting in reproductive isolation between the two species. Choice A is incorrect because freely interbreeding populations do not have prezygotic barriers. Choice B is incorrect because having the same mating behavior does not necessarily guarantee successful interbreeding. Choice D is incorrect because successful breeding with either species indicates that there are no prezygotic barriers present.

Question 19

A large population of animals is split in two by a physical barrier. Over time, the genetic make up of the two resulting populations becomes more and more different, until each population becomes a separate species. This is an example of

Accepted Answer

Allopatric speciation occurs when a physical barrier separates a population, preventing gene flow between them. Over time, random mutations and different selective pressures can lead to genetic divergence, ultimately resulting in the formation of two separate species. Sympatric speciation occurs without a physical barrier, through factors such as disruptive selection or chromosomal changes, but is not applicable in this scenario. Genetic drift refers to random fluctuations in gene frequencies within a population, while reproductive isolation is a consequence of speciation, not the cause.

Question 20

Which of the following is an example of reproductive isolation?

Accepted Answer

The answer of Which of the following is an example...

Quiz 18: Adaptation and Speciation