The major function of the immune system is to protect the host from environmental agents such as microbes or chemicals, thereby preserving the integrity of the body. This is done by the recognition of self and response to non-self.
Answer: If a cell has the ability to take in water, food molecule, and other necessary materials this indicates it is capable of nutrition. The answer can not be digestion or absorption because it's a term that talks about multicellular beings.
I think sperm is the answer
A, B, D, F are the gated embedded
proteins in model 1 allow potassium ions through the membrane. Sodium ions are
necessary for regulation of blood and body fluids, transmission of nerve
impulses, heart activity, and certain metabolic functions. Physiologically, it
exists as an ion in the body.