Answer:
troposphere
Explanation:
closest to Earth's surface
Answer:
(b) Digestive tract and liver
Explanation:
The digestive system consists of the digestive tract and liver. The digestive tract is made up of a large number of parts. These parts include the esophagus, stomach, intestines, rectum, etc. Food enters the mouth and travels down the digestive tract and out passing the rectum. The liver is where the blood passes through and it is responsible for many functions such as the metabolizing of fats and proteins, separating and storing vitamins and minerals, regulating different chemicals found in the blood, etc.
People with HIV are unable to fight off these rare diseases because they have a weakened immune system.
The responses observed in type IV hypersensitivities result from the action of T cells and phagocytes.
Hypersensitivity IV type, also called delayed-type hypersensitivity (DTH), involves T cell-antigen interactions that cause activation and secretion of cytokines. This type of hypersensitivity requires sensitized lymphocytes that respond 24–48 hours after exposure to soluble antigens. A type IV hypersensitivity reaction is a cell-mediated reaction that can occur in response to contact with certain allergens, resulting in what is called contact dermatitis, or in response to certain diagnostic procedures such as the tuberculin skin test. Certain allergens need to be avoided to treat this condition. Type IV hypersensitivity response is observed results from the action of T cells and macrophages while other types are mediated by antibodies. This reaction occurs at least 1–3 days after the initial exposure. Type IV hypersensitivity is the mechanism of many autoimmune disorders.
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Cells are combined in a structure called tissue wich have the same properties like the cells wich are formed by.