Question 1

Based on the data in the figure, a likely reason for speciation between these two sympatric species of frogs is:

Accepted Answer

The answer of Based on the data in the figure,...

Question 2

The two major forces contributing to allopatric speciation are:

Accepted Answer

Allopatric speciation occurs when populations are geographically isolated, leading to genetic drift and natural selection acting on the separated populations, causing them to diverge over time.

Question 3

Which of the following represents a prezygotic barrier to reproduction?

Accepted Answer

Behavioral isolation is a prezygotic barrier where differences in mating behaviors prevent different species from interbreeding. The other options are postzygotic barriers, which occur after fertilization.

Question 4

Two mammals, a sheep and a goat, produce offspring.Only the F₁ and F₂generations produce fertile offspring.This is occurs as result of:

Accepted Answer

Hybrid breakdown occurs when the first generation (F1) hybrids are viable and fertile, but the second generation (F2) or later generations are inviable or sterile. This explains why only the F1 and F2 generations produce fertile offspring in this scenario.

Question 5

Excellent examples of allopatric speciation can be seen:

Accepted Answer

Islands provide isolated environments where populations can evolve independently, leading to allopatric speciation.

Question 6

Hybrid breakdown is characterized by:

Accepted Answer

Hybrid breakdown refers to the reduced fitness or sterility of the progeny of hybrid individuals, which can occur in later generations rather than the immediate hybrid offspring.

Question 7

Hybrid sterility is NOT common when:

Accepted Answer

Hybrid sterility is a postzygotic barrier, meaning it occurs after fertilization. Prezygotic barriers prevent fertilization from occurring in the first place, so they do not lead to hybrid sterility.

Question 8

The continued geographic isolation of Kaibab squirrels from Abert squirrels will lead to:

Accepted Answer

The geographic isolation of Kaibab squirrels from Abert squirrels is an example of allopatric speciation, where physical separation leads to the evolution of new species.

Question 9

The evidence supporting Porto Santo rabbits as a new and recent species does not include:

Accepted Answer

The ability to produce fertile offspring with mainland rabbits under experimental conditions suggests that Porto Santo rabbits are not a distinct species, as species are typically defined by reproductive isolation.

Question 10

Which of the following statements about allopolyploidy is false?

Accepted Answer

Allopolyploidy itself does not account for a large portion of species diversity; it is one of many mechanisms contributing to diversity.

Question 11

In __________ speciation, a population forms a new species within the same geographical region as the original species.

Accepted Answer

Sympatric speciation occurs when a new species forms within the same geographical region as the original species.

Question 12

Approximately what fraction of flowering plants is polyploid?

Accepted Answer

The answer of Approximately what fraction of flowering plants is...

Question 13

Hybrid inviability and hybrid sterility are reproductive isolating mechanisms that are termed:

Accepted Answer

Hybrid inviability and hybrid sterility occur after fertilization, affecting the viability or fertility of the hybrid offspring, thus they are considered postzygotic barriers.

Question 14

Temporal isolation and mechanical isolation are reproductive isolating mechanisms that are classified as:

Accepted Answer

Temporal isolation and mechanical isolation are prezygotic barriers because they prevent mating or fertilization from occurring between different species.

Question 15

Allopolyploidy is a significant factor in the evolution of:

Accepted Answer

Allopolyploidy is particularly significant in the evolution of flowering plants, where it contributes to speciation and diversity by combining the genomes of different species.

Question 16

Mules are an example of:

Accepted Answer

Mules are an example of hybrid sterility because they are the offspring of a horse and a donkey and are typically sterile, meaning they cannot reproduce.

Question 17

Which of the following groups of organisms demonstrated a sudden appearance in the fossil record and continues to exhibit remarkable diversity today?

Accepted Answer

Flowering plants, or angiosperms, appeared suddenly in the fossil record during the Cretaceous period and have since diversified into a wide variety of forms, making them one of the most diverse groups of plants today.

Question 18

Polyploidy is much more common in:

Accepted Answer

Polyploidy is more common in plants than in animals because plants can often tolerate and even benefit from having multiple sets of chromosomes, which can lead to greater genetic diversity and adaptability.

Question 19

If a small population of mice colonizes a new area away from the range of the original species, the colony that is geographically isolated may eventually evolve into a new species.These events can be used to describe:

Accepted Answer

Allopatric speciation occurs when a population is geographically isolated, leading to the evolution of a new species due to the lack of gene flow and different selective pressures in the new environment.

Question 20

An organism with multiple sets of chromosomes from different species is called:

Accepted Answer

An allopolyploid is an organism that contains multiple sets of chromosomes derived from different species, resulting from hybridization and chromosome doubling.

Quiz 20: Speciation and Macroevolution