Nitrogen-fixing bacteria are capable of growing in a medium lacking organic Nitrogen. They convert (fix) atmospheric Nitrogen (Nitrogen is abundant in air) into organic substrates. Hence, they will grow in the enrichment medium described. This is the kind of medium used to isolate nitrogen-fixing bacteria.

Non-nitrogen fixing bacteria require an organic form of Nitrogen for growth. Hence, in a medium with no nitrogen, they will rely on the Nitrogen fixers. This means delayed growth for them.

A culture medium also has limited nutrients, so the slow growers will have little or no nutrients left.

Therefore, the Nitrogen fixers will have competitive advantage and significantly outnumber those incapable fixing nitrogen.

5 0

3 years ago

Which of the following is a population?

Marta_Voda [28]

Answer:

Explanation:

First, let’s define population. A population is all of the organisms of the same species that live in a certain area.

Now, let’s analyze the answer choices.

A: All of the different kinds of fish that live in a lake.

This is not a population, because a population is one species, and this is all the different species of fish.

B. All of the living and nonliving things that interact in and around a lake.

This is also not a population. A population is just one species, while this includes all the biotic and abiotic factors.

C. All of the trout that live in a lake.

This is a population. Trout are one species, and it is all the trout in one specific area.

D. . All of the fish, bacteria, and mammals that live in a lake

This is not a population. Fish, bacteria and mammals are too many species for a population.

Therefore, the correct answer is C. all of the trout that live in a lake.

6 0

3 years ago