Answer:
Immune system of the body helps in fighting with the infectious agents that are foreign for the body. So the immune system protects us from infection.
When any foreign substance(antigen) comes in the body B-lymphocyte recognize it by binding the antigen through its receptor. After recognizing the antigen, B cell divides into antibody-producing plasma cell and memory cell.
Antibodies produced by plasma cells help in destroying the antigen by getting the antigen recognized by phagocytic cells or by complement activation.
B cells are antigen-presenting cell which present antigen to T cell and then T cell activates and produce chemicals that kill the antigen. Therefore the immune system has many immune cells that activate when an antigen comes in the body. This is how the immune system functions.
LINKAGE
Independent assortment refers to the allele segregation of two different genes. They are expected to be segregated from each other independently.This is not seen in monohybrids, they are usually heterozygous for an allelic pair only. Link genes cannot assort independently. These are inherited together during meiosis phase of sexual reproduction. Usually genes that are close together will tend to stick together resulting into inheritance of genes as pairs.
Earwigs, slugs, and snails eat annual flowers out of gardens.
Animal cells form animals
Plant cells form plants
