50 POINTS.

PLATO USERS ( The Carrying Capacity of Ecosystems )

1. A population of foxes inhabits a small forest. The size of the population is currently below the forest's carrying capacity for the foxes. Which factor could cause an increase in the population's growth rate?

A. An increase in food availability increases the birth rate in the population.
B. A lack of mating opportunities increases the population's level of emigration.
C. The population's level of immigration falls below its level of emigration.
D. The population's birth rate falls below its death rate after a predator is introduced.

2. The__A__is an estimate of the fewest number of organisms a population needs to avoid extinction. This measurement will most likely__B__if the number of offspring each female in the population produces increases. If the population's__C__, this measurement will most likely increase.

A: Population Density / Carrying Capacity / Minimum Viable Population
B: Increase / Decrease / Be Unaffected
C: Death Rate Increases / Death Rate Decreases

3. Which term do biologists use to describe the average number of individuals of a species per unit area?

A. carrying capacity
B. population density
C. minimal viable population
D. survivability curve

A marsh supports a large population of cattails, which are tall wetland plants. Purple loosestrife, an invasive wetland plant, is introduced to the marsh. Both purple loosestrife and cattails require access to sunlight and space along the floor of the marsh to grow.

4. What effect will the growth of purple loosestrife have on the marsh's carrying capacity for cattails?

A. The carrying capacity will decrease because invasive species are typically predators of native species.
B. The carrying capacity will decrease because the cattails will have increased competition for resources.
C. The carrying capacity will increase because invasive species are typically beneficial to ecosystems.
D. The carrying capacity will increase because the cattails can use resources produced by purple loosestrife.

A population of 400 Mexican free-tailed bats roost inside a cave and forage for food at night. They primarily prey on insects, like moths. The bats' predators include hawks, owls, and snakes. A female bat typically gives birth to one offspring per year.

5. Determine whether (A-E) Scenarios will most likely increase or decrease the population size of the Mexican free-tailed bats.

Increase Population / Decrease Population

A: Populations of insects
in the area decrease.

B: Populations of owls
in the area increase.

C: Bats from a nearby
colony immigrate
into the population.

D: Some bats are
infected with a fatal
fungal disease.

E: Improved food quality
allows female bats to
have two breeding
cycles per year.