How is endocytosis involved in immune defense of the human body

What is point source pollution of an aquatic ecosystem? a) pollution of freshwater sources b) pollution from many sources that combine into one c) pollution that occurs over a wide area; water that runs off from fields, parking lots, and other land surfaces d) pollution that can easily be identified with a single discharge source, such as an open pipe which drains into a body of water

What are the base pairing rules? how does this allow for dna replication

Scientists that are involved in the creation of human growth hormone most likely work in which field?