Cells defend themselves from viruses, bacteria with armor of protein errors
Blood, urine, tissue/skin, saliva, hairs, etc.
Answer:
The CTL has specific receptors that can recognize infected or damaged cells.
Explanation:
The cytotoxic T cells (CTL) is a type of white blood cells that specifically helps in destroying virus-infected cells (also damaged cells and cancer cells).
This type of cells has a special receptor called T-cells receptors (TCR) which ones recognize specific antigens (molecule that stimulate the immune systems because are “strange” to them). Virus inside a cell could bind to a special molecule called class I MHC, this molecule moves the virus to the surface of the cell where it can be recognized by a CD8+ specific antigen-receptor of the CTL.
Mutations can be categorized based on the kind of effect they have on an organism. Blue eyes in humans are a result of a mutation in the OCA2 gene, which controls the production of pigment melanin in the iris.
This mutation is an example of a neutral mutation. Such mutations have no effect on an organism’s survival.