Answer:
In this given statement , the plastic base becomes negatively charged because plastic is an insulator . And the metal cup does not become charged because metal is a conductor.
Explanation:
<u>Reason behind , why plastic base becomes negatively charged -:</u> When a plastic base is rubbed with a dry cloth in the metal trophy, electrons are shifted from one material to the other. Thus, the substance that gains electrons (which is the plastic base) becomes negatively charged. thus , the plastic is an insulator , which causes charge (negative ) by rubbing.
<u>Reason behind , why the metal cup does not become charged -:</u> The metal cup is a conductor, and the surplus charge on the metal flows to the person who charges the cup and to the ground so that it is not charged. Thus, rubbing a metal can trigger hand\finger injury because metals generate excess heat in rubbing .
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
Troposphere. Hope this helps.
To get x on its own, you times the 8 over so the 8 cancels each other out on the LHS.
~ x > 32
(D)
