Question 1

The following pictures show a shark,which is a fish,and a dolphin,which is a mammal.The similar body types of these two species are due to

Accepted Answer

The similar body types of these two species are due to convergent evolution, which is a process where unrelated organisms evolve similar physical or behavioral traits to adapt to similar environments or ecological niches. In this case, both sharks and dolphins share a similar streamlined shape to help them move efficiently through the water. However, they have different evolutionary histories and are classified as different groups of organisms - sharks are fish, while dolphins are mammals.

Question 2

Polyploidy can lead to very rapid speciation in plants because

Accepted Answer

Polyploidy results in gametes with an altered number of chromosomes, preventing them from successfully fusing with gametes of the original species, leading to reproductive isolation and rapid speciation.

Question 3

Grizzly bears,whales,mice,and humans are very different genotypically and phenotypically.However,they do share some genotypic and phenotypic traits because they

Accepted Answer

Grizzly bears, whales, mice, and humans are all members of the animal kingdom and evolved from species that radiated from a common ancestral species millions of years ago. This means they share some genotypic and phenotypic traits due to their common ancestry, such as the presence of DNA and basic cell structures. They have also diverged from each other over time, resulting in the differences we see today.

Question 4

Sympatric speciation

Accepted Answer

Sympatric speciation occurs when a new species emerges from a population in the absence of a geographical barrier, meaning that the populations are not isolated from one another. While polyploidy can be a factor in sympatric speciation, it is not always the cause. Sympatric speciation can occur in both plants and animals.

Question 5

Which of the following is NOT due to the common ancestry of related species?

Accepted Answer

Analogous structures are not due to common ancestry but rather are the result of convergent evolution, where similar environments or selective pressures have caused different species to develop similar structures independently. Homologous structures, vestigial structures, and descendant structures are all due to common ancestry.

Question 6

Adaptive evolution

Accepted Answer

Adaptive evolution is the process by which natural selection improves the match between an organism and its environment over time. It involves the gradual genetic changes in a population that lead to an increase in the frequency of traits that improve survival and reproductive success. This can result in the development of new species or the adaptation of existing ones to new habitats or ecological niches. A and B are incorrect as they do not accurately describe adaptive evolution. D is incorrect as it implies that many species are evolving in the same direction, which is not necessarily the case.

Question 7

Mass extinctions frequently result in adaptive radiation because they lead to

Accepted Answer

Ecological isolation in other species allows for the survival of different species in different niches, leading to adaptive radiation.

Question 8

In the following illustration of adaptive radiation of mammals,which is the ancestral species?

Accepted Answer

Adaptive radiation is a process in which a single lineage diversifies into multiple species that occupy different ecological niches. In this illustration, we can see that Morganucodon is the oldest and most ancestral species. It gave rise to different groups of mammals through adaptive radiation, such as Brontotherium, Woolly mammoth, and Grizzly bear. Therefore, the best choice as the ancestral species is D, Morganucodon.

Question 9

In general,geographical isolation occurs when

Accepted Answer

Geographical isolation occurs when populations are separated by a distance that is great enough to limit gene flow. This can occur due to physical barriers such as mountains, bodies of water, or other obstacles that prevent individuals from moving between populations. In this way, genetic differences can accumulate between populations over time, leading to the evolution of new species.

Question 10

The two squirrel species shown in the following figure arose from the same ancestor.The Kaibab squirrel lives on the north rim of the Grand Canyon and Abert's squirrel lives on the south rim.Which is the most likely explanation for their speciation?

Accepted Answer

The formation of the Grand Canyon split the ancestral squirrel population into two isolated populations with different habitats. Over time, natural selection and genetic drift caused each population to evolve differently, leading to reproductive isolation and the development of two distinct species.

Question 11

Adaptive evolution allows species to

Accepted Answer

Adaptive evolution refers to changes in a population's genetic makeup that enable it to better survive and reproduce in its environment. These changes may include the emergence of new traits or the modification of existing ones. In this way, adaptive evolution allows species to adjust to environmental changes, such as shifts in climate, the appearance of new predators or competitors, or the spread of diseases. The other options are incorrect because reducing the mutation rate would limit genetic diversity and the potential for adaptation, decreasing genetic variation would limit the ability to respond to environmental changes, and hybridization involves the mixing of genetic material from two or more different species, which may or may not lead to adaptive changes.

Question 12

Adaptive radiation gives rise to

Accepted Answer

Adaptive radiation is the process by which a single ancestral species diversifies into many different descendant species, each occupying a different ecological niche. Therefore, the best choice is A, which indicates that adaptive radiation gives rise to many descendant species.

Question 13

Vertebrates,animals with backbones,and arthropods,including insects,are only distantly related.The arthropod eye evolved independently of the vertebrate eye.Therefore,the arthropod eye and the vertebrate eye are ________ structures in relation to each other.

Accepted Answer

The fact that the arthropod eye and the vertebrate eye evolved independently of each other means that they are not homologous (derived from a common ancestor) or vestigial (having lost its original function), but rather analogous (having similar functions but different origins). Therefore, the best choice is C) analogous. D) hybrid is not a valid option as it does not accurately describe the relationship between the arthropod and vertebrate eyes.

Question 14

Vertebrates are a group of related animals with a backbone.All vertebrates have basically the same eye structure.Therefore,the vertebrate eyes are

Accepted Answer

Homologous structures are anatomical structures that have the same evolutionary origin but may have different functions in different organisms. Since all vertebrates have a similar eye structure, it suggests that they share a common ancestor and that the eyes are homologous structures. Vestigial structures are structures that have lost their original function through evolution, which does not apply to the vertebrate eyes. Analogous structures are structures that have the same function but different evolutionary origins, which is not the case for vertebrate eyes. Convergent structures are structures that have evolved independently in different organisms to serve a similar function, which also does not apply to vertebrate eyes.

Question 15

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

Accepted Answer

Geographic isolation refers to physical barriers that prevent two populations from interbreeding. In this case, option B describes two bird populations that live on adjacent mountains with a narrow valley between them, which does not provide a complete physical barrier between them. Therefore, it does not provide an example of geographic isolation.

Question 16

Polyploidy can lead to

Accepted Answer

Polyploidy can lead to changes in the number of chromosomes, which can result in reproductive isolation between organisms with different numbers of chromosomes. This can lead to the formation of new species.

Question 17

Polyploidy in plants can lead to

Accepted Answer

The answer of Polyploidy in plants can lead to
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Question 18

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

Accepted Answer

The scenario described in the question is an example of allopatric speciation, where a physical barrier separates a population into two or more geographically isolated groups. Over time, genetic differences accumulate due to factors such as mutation, genetic drift, and natural selection, eventually resulting in the formation of separate species. Sympatric speciation, on the other hand, occurs when a new species arises within the same geographic area as the parent population, without physical separation. Genetic drift and natural selection are mechanisms that can drive speciation, but alone they do not result in the physical separation required for allopatric speciation to occur.

Question 19

Convergent evolution frequently occurs when two unrelated species

Accepted Answer

Convergent evolution occurs when two unrelated species evolve similar traits that allow them to adapt to similar environments or ecological niches. Therefore, they live in similar habitats. Hybridization, predator-prey relationships, and occupying different ecological niches are unlikely to lead to convergent evolution.

Question 20

Today's diversity of mammals originated with an adaptive radiation that occurred 65 million years ago.This adaptive radiation occurred because

Accepted Answer

The extinction of the dinosaurs at the end of the Cretaceous period created ecological niches that were previously unavailable, allowing for the diversification of mammals. Additionally, the removal of large predatory dinosaurs also allowed for smaller mammals to thrive and evolve.

Quiz 15: The Origin of Species