It is also known as a rescue agent
Answer:
Euhaline ⇒ Polyhaline ⇒ Mesohaline ⇒ Oligohaline
Explanation:
Let's first define each of these levels:
- Polyhaline: a category of salinity that has medium-high levels of salt
- Mesohaline: a category of salinity that has medium levels of salt
- Oligohaline: a category of salinity that has low levels of salt
- Euthaline: a category of salinity that has high levels of salt
Now, we can order these in decreasing order of salinity:
Euhaline ⇒ Polyhaline ⇒ Mesohaline ⇒ Oligohaline
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:
Las células eucariotas tienen dos funciones primordiales, alimentarse y reproducirse. Las células eucariotas, al igual que las procariotas, llevan a cabo tres funciones esenciales: la nutrición, la relación con el medio y la reproducción. ... Célula con un núcleo definido por una membrana que contiene el material genético.
Explanation:
