T cells
The immune response to a transplanted organ consists of both cellular (lymphocyte mediated) and humoral (antibody mediated) mechanisms. Although other cell types are also involved, the T cells are central in the rejection of grafts. The rejection reaction consists of the sensitization stage and the effector stage.
Answer:
The valence electrons have a role in the bonding of two atoms. The nuclei of each atom are drawn together by their attraction to the valence electrons of the other atom. As the atoms are drawn together by their attractions, electrons from each atom are drawn to the nuclei of both atoms, where they are "shared."
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Answer:
D is rhe answer of rhis question.
Explanation:
collection of cells make tissue, collection of tissues form organ, similarly group of organs combine to form a system and when these systems combine it forms a whole body of organism.
Answer:
e. cutin
Explanation:
Plant exhibit many variations to withstand the temperature variations, desiccation and increased UV exposure which are some of the factors associated with land habitat. Cutin is a waxy substance that is found in the outer walls of the epidermal cells of plants. Cuticle in plants serves to make the outer most covering of aerial parts of the leaves and non-woody stem of herbaceous plants. The cuticle is made of cutin.
Cutin serves to protect the plant’s aerial surfaces from excess water loss. It also filters the excess UV light and thereby protects the underlying plant parts. The thickness of the cuticle varies in different plants depending upon the environmental conditions. The leaves of plants adapted to hot, dry climates have thick cuticles. The thickness of the cutin layer also varies in different parts of a plant. For example, the upper epidermis of leaf generally has a thicker cuticle than the shaded and relatively cooler lower epidermis.
Answer:
The main idea in a given piece of reading is implied by the introductory paragraph, and, or several meaning sentences that are in subsequent paragraphs.
Explanation:
The main ideas in the a given piece of work, specifically reading is contained in the first paragraph of the piece of writing. The first paragraph can be used to imply the main ideas in a topic without necessarily revealing it. The first concepts, terms, illusion and characters mentioned, certainly we can deduce the main idea.
Several sentences in paragraphs that carry almost similar, related and interrelated facts, in most cases are very essential in explaining the main idea. By looking at them in various paragraphs, one is able to find the sole message being communicated.