Question

Azotobacter is a genus of bacteria that live in soil and have the following characteristics: They are bacilli. They are gram-negative. They are obligate aerobes. They can fix nitrogen. (Unlike some other nitrogen-fixing bacteria, which associate with the roots of plants, Azotobacter species are free-living.) Select the four statements that are true for bacteria in the genus Azotobacter. View Available Hint(s) Select the four statements that are true for bacteria in the genus Azotobacter. They can carry out anaerobic respiration in an environment that lacks O2. They are shaped like rods. They use O2 for cellular respiration. They have the appearance of coils or corkscrews. They require amino acids or other organic molecules as a source of nitrogen. They can convert atmospheric nitrogen to ammonia. They have a relatively thin layer of peptidoglycan in their cell wall. They appear purple after Gram staining. They are poisoned by O2.

Answer 1

The four statements that are true for bacteria in the genus Azotobacter are:

They are shaped like rods, They use O2 for cellular respiration, They can convert atmospheric nitrogen to ammonia, and They have a relatively thin layer of peptidoglycan in their cell wall

Step-by-step explanation:

Azotobacter is a bacterial genus commonly found in soils, with the following characteristics:

1) They are bacilli, it means bacteria with rod shape.

2) gram-negative.

Looking at the content of peptidoglycan present in the cell wall of a bacteria, we can distinguish two different types: gram-possitive (bacterias with a thick layer of peptidoglycan in their cell wall, that acquires a violet colour in the Gram reaction, because it fixs the violet dye) and gram negative (with thin layers of peptidoglycan that does not fix the violet dye, but reacts with safranin, getting a red color).

3) obligated aerobes. This characteristic refers to the requierement of oxigen for bacteria life. They can not live in anoxic (without oxigen) conditions.

4) can fix nitrogen. So Azotobacter can take atmospheric nitrogen and fix it as ammonia.

5) free living. This kind of bacteria can live without associating to another organism. They can live by itself.