What is the function of the immune systems

The major function is to protect the host for environmental agents, like microbes or chemicals. Also, the immune system is to keep infectious microorganisms, like viruses and bacteria, out of the body and to destroy any infectious microorganisms that do invade the body.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

answer; autosomal;