Question 1

Some freshwater snail eggs are accidentally introduced into a new habitat that is geographically isolated from the original population.Which of the following must occur before these snails are described as two separate species?

Accepted Answer

A)  gene flow 
B)  sympatric speciation 
C)  adaptation 
D)  genetic divergence

Question 2

According to the biological species concept,a species is defined when individuals of the same species

Accepted Answer

A)  differ widely in their DNA sequences. 
B)  always have the same physical traits. 
C)  are capable of interbreeding and producing fertile offspring. 
D)  must reproduce asexually.

Question 3

Which of the following statements is true about adaptation?

Accepted Answer

A)  It is large-scale movement of a single species over a new geographic area. 
B)  It occurs when a more adapted species causes the extinction of a less adapted one. 
C)  It is the process by which natural selection improves the match between an organism and its environment over time. 
D)  It is an increase in the adaptiveness of many species that have already evolved.

Question 4

Using the biological species concept as a method of defining a species is NOT useful for

Accepted Answer

A)  species whose ranges overlap. 
B)  species that cannot produce hybrids. 
C)  organisms known only from fossils. 
D)  organisms that reproduce sexually.

Question 5

Which of the following is an example of a postzygotic barrier?

Accepted Answer

A)  The gametes cannot join. 
B)  The zygote fails to develop. 
C)  The breeding seasons are different. 
D)  The courtship behaviors are different.

Question 6

Two biologists discover two populations of toads living in the same area.Morphologically,these two populations are different.The toads in one population have much wider heads and darker coloration than the second population.One of the biologists suggests names for the two new species.The second biologist questions whether the two populations are separate species.Why is the second biologist hesitant to declare these populations are two species?

Accepted Answer

The answer of Two biologists discover two populations of toads...

Question 7

This figure shows two squirrels that represent two separate species.Explain how the geographic barrier between these two populations led to the formation of two distinct species.

Accepted Answer

The answer of This figure shows two squirrels that represent...

Question 8

Which of the following is MOST likely an example of coevolution?

Accepted Answer

A)  The color of a rodent's hair changes to better match a new environment. 
B)  A parasitic worm develops a new mechanism to attach to the gut lining of an organism that has a special adaptation designed to shed parasitic worms. 
C)  Two different species of plants produce flowers that are the same color,which attracts honeybees. 
D)  Two unrelated rodent species on different continents develop flaps of skin between their front legs and bodies that allow them to glide between trees.

Question 9

Two species live in the same area but breed in different parts of their habitat.These species are

Accepted Answer

A)  geographically isolated. 
B)  ecologically isolated. 
C)  artificially isolated. 
D)  likely to produce hybrids.

Question 10

In general,geographical isolation occurs when

Accepted Answer

A)  populations migrate to new environments. 
B)  gene flow is reduced by more than 75 percent due to climate change. 
C)  mutations overcome genetic drift across physical barriers. 
D)  populations are separated by a distance that is great enough to limit gene flow.

Question 11

Which of the following must occur for one species to split into two or more species?

Accepted Answer

A)  The species must move into a new habitat. 
B)  DNA sequences of genes must accumulate differences. 
C)  Morphological changes must be obvious within the population. 
D)  One species must undergo geographic isolation.

Question 12

Geographic isolation limits the ________ between separated populations of a species.

Accepted Answer

A)  genetic differences 
B)  adaptation 
C)  directional selection 
D)  gene flow

Question 13

Close ecological interactions between two different species may lead to

Accepted Answer

A)  allopatric speciation. 
B)  sympatric speciation. 
C)  coevolution. 
D)  geographic isolation.

Question 14

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

Accepted Answer

A)  The members of two populations of birds living in neighboring forests freely interbreed. 
B)  One species of cichlid has the same mating behavior as another cichlid species in the same lake. 
C)  The gametes of one species of orchid in a rainforest are unable to fuse with the gametes of another species of orchid in the same rain forest. 
D)  Two species of wildflowers mate and produce a hybrid that is capable of successfully breeding with either species.

Question 15

Individual organisms with inherited characteristics that enable them to survive and reproduce are said to have greater ________ fitness than individuals who fail to survive and reproduce.

Accepted Answer

The answer of Individual organisms with inherited characteristics that enable...

Question 16

Populations within a species are connected by

Accepted Answer

A)  gene flow. 
B)  speciation. 
C)  continental drift. 
D)  genetic drift.

Question 17

Choose two different reproductive barriers that lead to sympatric speciation and explain how they work.

Accepted Answer

The answer of Choose two different reproductive barriers that lead...

Question 18

The formation of a new species

Accepted Answer

A)  can occur any time genetic divergence occurs. 
B)  can only occur when two populations are geographically isolated. 
C)  can only occur when two populations are sympatric. 
D)  is a process that stopped occurring thousands of years ago.

Question 19

A lizard is attacked by a bird.The lizard escapes and survives without his hind legs.Fortunately for this lizard,the loss of his hind limbs allows him to live within a smaller crevice than other lizards of the same species,so he experiences less competition.Which of the following is true for this lizard?

Accepted Answer

A)  The loss of his legs provided an advantage within his environment. 
B)  The loss of his hind legs would be considered an adaptive trait. 
C)  A lack of hind limbs should become more common in this population. 
D)  This lizard will be unable to reproduce.

Question 20

Based on the ________ species concept,organisms that interbreed and produce fertile offspring are most likely classified as species.

Accepted Answer

The answer of Based on the ________ species concept,organisms that...

Exam 13: Adaptation and Species