Natural Selection Carrying Capacity

A scientist was studying a population of fish in a pond over a period of 10 years. He observed that

the population increased each year for 3 years, and then remained nearly constant for the rest of

the study. The best explanation for this observation is that the population had

• stopped reproducing

• reached carrying capacity

• mutated into a different species

• run out of food and all died

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Mice produce a large number of offspring all year long, yet the number of mice within a given population changes very little from year to year. The stability of the population size is most likely the result of

• mice continuing to reproduce when its population is large

• the survival of more female mice than male mice

• the development of mutations in young mice

• limiting factors that keep the population in check

Tags

NGSS.MS-LS2-4

One species of Galapagos finches, the cactus finch, eats insects off cactus plants. A disease kills off most of the cacti in the Galapagos Islands.

Which of these most likely would happen to the carrying capacity of the island?

• It would increase a small amount since the insect population would decrease.

• It would remain about the same since the finches would change to a different diet.

• It would decrease a lot because there is less to eat.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

The picture to the right represents a sunny, dry desert.

Which factor most likely limits the desert’s carrying

capacity for plant life?

• the number of animals that eat plants

• the amount of sunlight

• the availability of space to grow

• the availability of water

Tags

NGSS.MS-LS2-1

What point on the graph represents the carrying capacity?

• A
• B
• C
• D