Answer:
The most closely related are amphibians and reptiles.
The least related are amphibians and mammals
Explanation:
Amphibians broke off from reptiles, birds, and mammals around 260 millions years ago and next up are the reptiles which broke off around 225 million years ago. So they are the most closely related
Mammals are the last to break off, around 200 million years ago. So they are the least related to amphibians.
Hydrophonic plants are plants that is living in the lands,
and obviously the aquatic plants that are typically used to style aquariums.
However, the bubbles you can perceive in an aquatic plant can perhaps be a source
of oxygen which is recognized as one of the products of plants as well as human respiration. The bubbles
are oxygen and are created from the thylakoid membrane in the chloroplast over photosynthesis.
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.
