Answer:
CD4 on the surface of helper T-cells.
Explanation:
MHC class II ( major histocompatibility complex) molecules are processed from the exogenous source. The presentation of antigen on cells are important for the adaptive immune response.
MHC class II interact with CD 4 present on the surface of T helper cells. This interaction is important for the generation of an immune response. Helper T cells can release cytokines and can perform phagocytosis.
Thus, the correct answer is option (C).
Pollution adds heat to the air. for example: gas and smoke from cars and trucks etc. climate change will be affected because the heat will cause the weather and atmosphere around to get hotter. clearing pollution will keep the air cleaner.
The hemoglobin that is about 65% saturated with o2 in a healthy resting person Systemic veins & pulmonary arteries.
<h3>Define Hemoglobin?</h3>
Hemoglobin is a protein in red blood cells that takes oxygen to body's organs and tissues and elates carbon dioxide from organs and tissues back to your lungs.
Thus, Systemic veins & pulmonary arteries are correct.
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In humans, the medulla region of the brain is mainly responsible for the regulation process of respiration. It is also called the respiratory rhythm centre. The chemosensitive area located near the respiratory centre sends signals across nerve impulses to alter the rate of expiration to eliminate compounds.
