B. Cytoplasm- is made up of a jelly-like substance composed of mainly water and found between the cell membrane and nucleus. The cytoplasm makes up most of the body cells which hold organelles as well.
Answer:
Nitrogen is present in the atmosphere in a molecule form about 78 percent. This nitrogen comes to the earth with the water through rainfall. Some nitrogen fix by beneficial microorganisms such as Cyanobacteria and Azotobactor which are present in the roots of higher plants. These microorganisms convert nitrogen molecule into nitrates and used by the plants. There are some other microorganisms which again convert nitrate into nitrogen molecules, called denitrifying bacteria and nitrogen molecule goes to the atmosphere again and complete the cycle.
The occupation of different niches on the open plains and woodlands of Africa by the zebras and the wildebeests is a result of niche partitioning. The zebras and the wildebeests in a common niche would compete for food, water, shelter, and space. This competition would affect the population growth of the two species by negatively affecting their reproductive capabilities. Thus, in the same habitat, the two species choose to occupy two different niches such that the competition between them is minimised. Hence they end up in separate niches.