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).
Answer:
Mutualism
Explanation:
Organisms in an ecosystem interact with one another from time to time. The close interaction between two organisms is referred to as SYMBIOSIS. Symbiosis is of different types depending on the how it affects the involved organisms. The example in this question depicts MUTUALISM.
Mutualism is the type of symbiotic relationship between two organisms in which both organisms benefit from the relationship. This is the case of the LICHEN, which involves the Algae and Fungi. The algae benefits by making use of the water and minerals supplied by the fungi while the fungi benefits by using the food the algae produces via photosynthesis.
A basic tenet of modern biology, first stated by Matthias Schleiden and Theodor Schwann in 1838–39, that cells<span> are the basic units of structure and function in living organisms. ... A </span>theory<span> of heredity must be reconciled with the </span>cell theory<span>.</span>
They're called Enzyme. They're made up of proteins. They act as a biological catalysts that can speed up chemical reaction. They have an active site that certain substrates binds into it and form a product. Enzyme works under optimum pH and temperature and the active sites are not changed unless denatured.
During the day the sun burns up and the sand soaks up the heat causing a oven effect.
<span>While at night the wind will blow, and the sun is gone so the effect is like garages in the night. A great way to Yahoo or google search is "Desert climate and effects."</span>