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.
Carbon dioxide gas and oxygen gas
Its the fourth one hope i helped
Answer:
they are light years away
Explanation:
when you look at the sky you are looking at about 6 million years in the past because time travels differently between space and our atmosphere. That's why astronauts can feel like they have been gone for 3 days but really for 3 months.
Key point:
Light travels differently between space and Earth
