Down's syndrome, also known as Trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21.
This occurs due to a process called nondisjunction, where the chromosomes fail to separate properly during cell division (meiosis), resulting in an extra copy of chromosome 21 being inherited.
Cytotoxic T cells are a type of T lymphocyte that plays a crucial role in eliminating infected cells or tumor cells from the body.
They recognize and bind to specific antigens presented on the surface of infected cells or tumor cells, and then release cytotoxins, such as granzymes and perforin, which form pores in the plasma membrane of the target cell, leading to cell lysis and death.
Collagen and elastin fibers (which provide structure and elasticity)
A layer of dead cells is actually a characteristic of the epidermis, the outermost layer of skin, where dead skin cells are constantly shed and replaced by new ones.
Rennin (also known as Chymosin) is an enzyme produced in the stomach of ruminant mammals, such as cows, and is also present in the gastric juice of humans.
It helps to coagulate milk by converting casein, a milk protein, into a gel-like substance, causing the milk to curdle.
This process helps to slow down the digestion of milk and allows for better absorption of nutrients.
IgE antibodies are responsible for triggering an allergic response when they combine with an allergen.
This binding causes mast cells to release histamine and other chemical mediators, leading to allergic symptoms such as itching, swelling, and increased mucus production.
When a population is small, it is more susceptible to genetic drift, which is the random change in the frequency of a gene or trait in a population over time.
This is because there are fewer individuals and therefore less genetic diversity, making it more likely that chance events will significantly influence the gene pool.
