Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Answer:
A plant cell contains a large, singular vacuole that is used for storage and maintaining the shape of the cell. In contrast, animal cells have many, smaller vacuoles. Plant cells have a cell wall, as well as a cell membrane. In plants, the cell wall surrounds the cell membrane.
Explanation:
air, water, and ground pollution! hope o helped
<span>Nervous system is a network of specialized cells that monitors the internal and external environment and initiates commands through which the body reacts.
Nervous system is very important part of our body because it is the system which is controlling our body. If there is no nervous system we could not perform any function. It sends the message to and from the brain to all parts of body.</span>
