Answer:
Helper T cells stimulate B-cells to produce antibodies and killer T cells to destroy the non-self cells. Cytotoxic T cells on the other hand are direct attack cells. They can kill the micro organisms by creating pores on the invader's cell.
Explanation:
T lymphocyte mediated immunity of cell mediated immunity do not secrete antibodies but they help stimulate the B cells to produce them. Immature T cells are produced in bone marrow from where they migrate to thymus via blood. In the thymus maturation of T cells occur and then they migrate to lymphoid tissue and get differentiated into three types:
a. Helper T cells: As the name suggests, they help in activating other immune cells, in other terms they are the regulator of virtually all functions of immune system. Protein mediator called lymphokines are produced by these helper T cells in order to regulate the immune functions. Some examples of these lymphokines are: Interleukin-2 interleukin-3, interferon gamma. T helper cells stimulate the B-cells to produce antibodies.
b. Cytotoxic cells or killer T cells: The lymphokine interleukin-2 is responsible for the growth and proliferation of both cytotoxic T cells and suppressor T cells. With the help of receptor proteins on the surface of killer T cells, they bind to the specific antigen. After binding, they secrete a pore forming protein called perforins which create pores on the invaders cell membrane for water to enter into it thereby cell swells and finally lyse.
c. Suppressor T cells: They suppress the function of above two T cells.
Answer:
The primary types of human hair used in forensic investigations come from either the scalp (head) or pubic regions.
Explanation:
Hope this helps.
Answer: Option B) each parental strand serves as a template for the synthesis of a complementary strand
Explanation:
In semi-conservative DNA replication,
- a parent double-stranded DNA splits in two.
- Each strand is then read by the enzyme, DNA polymerase, to ensure accurate replication of a newly synthesized strand
- the new strand contains nucleotides that are complimentary to free nucleotides present in the parent strand.
Thus, option B perfectly describes semi-conservative replication of dna
Generalized anxiety disorder
This is a chronic disorder that
involves consistent and severe worry about so many things. It is not easy for persons
with this disorder to control their worry. They anticipate and wait for the
worst even when there is no visible reason to be worried. This disorder occurs
along with other anxiety or mood disorders and it can be a long-term challenge. From the question given above, Jonah is most likely to be
diagnosed with generalized anxiety disorder.
The answer is the letter C
