Select the scenarios that describe a biotic factor that is density dependent. Select the TWO answers that are correct.

1. Fir trees grow in number, increasing the amount of food available for moose.

2. Heavy and continuous rains flood the land, submerging habitats.

3. Lightning strikes a tree and begins a fire that clears the land.

4. Ticks infesting moose weaken the moose's health and reproductive success.

5. Frigid temperatures flow into the area, causing hypothermia and death.

1 and 4

Explanation:

A density dependent biotic factor is a biological component of an ecosystem whose activities or effects on a population's growth and size causes the density of the population to vary. In other words, they possess the quality of affecting the growth and size of a population, which in turn affects the density of the population.

Therefore, from the options given in the question, the scenarios that describe a biotic factor that is density dependent are seen in option 1 and option 4. Fir trees and ticks are all biotic factors whose activities and effect on the growth and size of the moose population makes the population density of moose to vary.

The correct options are:

1. Fir trees grow in number, increasing the amount of food available for moose.

4. Ticks infesting moose weaken the moose's health and reproductive success.