UNIT 7 Natural Selection REVIEW

Which of the following is a factor in natural selection?

• Individuals of species compete with one another to survive.

• All species are genetically diverse.

• Individuals better able to adapt to changes leave more offspring.

• All of the above.

Individuals that are better able to cope with the challenges of their environment tend to

• Increase in population over time.

• Decrease in population over time.

• Leave fewer offspring than those less suited to the environment.

• Both (a) and (c)

Starting in 1954, commercial fishers in the northwest Pacific were paid by weight, rather than by the individual fish, for pink salmon. The fishers increased the use of a type of net that selectively catches larger fish. Which of the following effects did this change in fishing technique most likely have on the salmon population over the next 20 years?

• The average body size of the salmon population decreased significantly.

• The average body size of the salmon population increased significantly.

• The average body size of the males in the salmon population increased, and the females stayed the same.

• None of the above.

The Asian shore crab invaded parts of the eastern coast of the United States about 15 years ago. The Asian shore crab preys on blue mussels. In the time since the Asian shore crab arrived, the average shell thickness of the blue mussel population has increased.

Which of the following is the most likely reason that this increase in shell thickness has occurred?

• Blue mussels with thick shells attract more crabs that mussels without thick shells.

• Blue mussels with thick shells grow in larger colonies than mussels without thick shells.

• Blue mussels with thick shells catch more food per day than mussels without thick shells.

• Blue mussels with thick shells survive and reproduce more successfully than mussels without thick shells.

The process in which organisms with traits well suited to an environment are more likely to survive and to produce offspring is

• Natural selection.

• Genetic principles.

• Origin of species.

• Trait mechanism.

The theory of ‘common descent with modification’ states that all modern organisms

• can change in response to environmental change

• are descended from a single ancestral species

• can be arranged in a linear order from “least evolved” to “most evolved”

• Have not changed over time

which of the following is an example of microevolution?

• a. the evolution pesticide resistance in pests

• b. the increase in size, over time, of the horse species.

• c. the change in color of the peppered moth due to pollution

• Both A and C

The fossil record provides evidence that

• Fossils cannot be dated.

• All species were formed during Earth’s formation and have changed little since then.

• The fossilized species have no connection to today’s species.

• Older species gave rise to more-recent species.

Structures with the same parts but have different functions, suggesting that organisms with a backbone share common ancestry is called…

• Not related

• Not homologous

• Homologous

• Young in origin

Structures with no function that are remnants of an organism’s evolutionary past are

• Not visible organisms

• Young in origin

• Vestigial

• Useful to the organism