<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
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cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
Place the object on the stage of the microscope
Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Mitosis is important because the organism must:
1. replace cells that have worn out or died
2. repair tissue that is damaged
3. add cells in order to grow
4. make new kinds of cells in order to develop
Answer:
C
Explanation:
Ice-covered surfaces are highly reflective of the sun's rays therefore prevent those areas from warming as much as the areas where the ice is replaced with darker, less reflective surfaces which absorb heat and thus contribute more to global warming. Albedo is the percentage of radiation reflected by the earth's surface. Clear surfaces have greater albedo values than dark surfaces.
Answer:
Option B, Apply auxin directly to the lower part of the stem opposite from the direction you want the stem to bend.
Explanation:
Options for the question are
A) Apply auxin directly to the shoot tip on the side to which you want the tip to bend.
B) Apply auxin directly to the lower part of the stem opposite from the direction you want the stem to bend.
C) Inject compounds that block auxin receptors into the part of the stem opposite from the direction you want the stem to bend.
D) Plant the roots in two different pots, and apply auxin to the root bucket that is on the same side as the direction you want the plant to bend.
Solution
Auxin is responsible for stem elongation by inhibiting growth of lateral buds. The movement of auxin is opposite to the direction of elongation of cells. Generally, Auxin moves to the dark side which is opposite to the direction i.e the lighter side in which cell elongate . Due to this growth pattern, the stem tip gets curved towards the light.
Hence, option B is correct
