I guess it would have to be A
Answer:
Presence of specific antigen receptors on the surface of Immunocompetent B and T cells make them to generate immune response against specific antigens only.
Explanation:
The cellular and antibody-mediated immune responses are specific in nature. This means these immune responses are generated for particular foreign molecules or antigens only. These immune responses include B and T lymphocytes. Before T cells leave the thymus or B cells leave the red bone marrow, they develop immunocompetence. Immunocompetence is the ability to carry out adaptive immune responses. During this process. B cells and T cells make distinctive proteins and insert them into their plasma membranes. Some of these proteins function as antigen receptors capable of recognizing specific antigens. This is why the B and T cell-mediated third line of defense are specific in nature.
For example, antibody-mediated immune responses generate the memory cells for most previously encountered antigens to ensure the generation of more rapid and vigorous response during any further encounter with the same antigen.
Rotation = pivot
no move = suture
side to side = glide
back and forth = hinge
32 predators were removed between 1907 & 1939
Stars begin as vast clouds that are called Molecular clouds, or Nebulae.
Nebulas are produced of the hydrogen in the molecular form (H2), dust,
helium and other ionized gases. Aurora is a natural display of glowing
light in the night sky, connected with the magnetic field of the planet.
Protostar is an undeveloped star in it`s early stages of creation. It
comes after the stage of Nebula. White Dwarf is the last phase of the
star`s life. Answer: B ) Nebula.
