Answer:
The answer would be A
PLEASE MARK ME BRAINLIESTY
THE ANSWER IS A BECAUSE IT GROWS VERY FAST UP IN A FAST DIRECTION
THANKS
Explanation:
3. Mechanical energy is the energy used by organisms to function and move.
3. The conservation of energy is the process in which organisms use up the energy in a cycle where nothing is wasted.
Hope it helped,
Happy homework/ study/ exam!
Answer:
The pollen grain is creating a tube down the style of the flower. <u>It is necessary as that is how the pollen is able to travel down the style into the ovary where the baby seed is located. This is how the seed is fertilized, and is ready for reproduction.</u>
Answer:
The information carried by DNA is incorporated in a code specified by the: specific nucleotide sequence of the DNA molecule. The enzyme DNA ligase is responsible for: linking short DNA segments.
Explanation:
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.
