What happens when an antigen is introduced into an organism? A. Myeloma cells are activated.
B. Monoclonal antibodies are produced from plasma cells
C. Polyclonal antibodies are produced from plasma cells.
D. Polyclonal antibodies are produced from somatic cells.

B. Monoclonal antibodies are produced from plasma cells

Explanation:

An antigen is a molecule present on the surface of a pathogenic organism and they are capable of generating an immune response by binding to specific antibodies (immunoglobulins) that are secreted by lymphocytes B cells of the immune system. B cells are a type of white blood cell that plays key roles during humoral immunity of the adaptive immune system. When an antigen is introduced into the organism, a specific lineage of B cells proliferate, in a process known as monoclonal expansion.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.