AP BIOLOGY

Detailed explanation-1: -Nitrogen makes up part of the chlorophyll in plants. Chlorophyll is the green part of leaves and stems. Light energy is taken by the chlorophyll and used to make sugars for the plant.

Detailed explanation-2: -Algal cells are natural fertilizer and nowadays it is used worldwide, without any side effect, Algal cells have specific cells called heterocyst and are the site of nitrogen fixation. Algae are able to convert unavailable dinitrogen into bioavailable ammonia.

Detailed explanation-3: -The most important part of the cycle is bacteria. Bacteria help the nitrogen change between states so it can be used. When nitrogen is absorbed by the soil, different bacteria help it to change states so it can be absorbed by plants. Animals then get their nitrogen from the plants.

Detailed explanation-4: -Denitrifying bacteria convert the nitrate back into nitrogen gas, which reenters the atmosphere.