D. fingernails
Skin, hair, and vertebrae are all the outer layer of the body and protect the body. The fingernails aren't part of that.
At first the cells have the same number of chromosomes as mitosis. DNA replication occurs, giving a total of 46<span> chromosomes (or </span>23<span> chromosome pairs) and </span>92 chromatids<span> (or </span>46 chromatid<span> pairs).</span>
Answer: humoral immune response
The main antibody isotypes in the influenza-specific humoral immune response are IgA, IgM and IgG. Mucosal or secretory IgA antibodies are produced locally and transported along the mucus of the respiratory tract by transepithelial transport and can afford local protection from infection of airway epithelial cells.
