Answer:
B. Non living components of an ecosystem
Helper T cells <span>are required for almost all </span>adaptive immune responses<span>. They not only help activate B </span>cells to<span> secrete antibodies and macrophages </span>to<span> destroy ingested microbes, but they also help activate cytotoxic </span>T cells to<span> kill infected target </span>cells<span>.</span>
Answer:
The nitrogen cycle could not exist without first nitrogen. The cycle is about this specific element which goes to show that if this element is not present then, there will not be any nitrogen cycle. Also, an important factor for the cycle is the presence of the bacteria and other microorganism which are needed for the fixation.
Answer:HOW DO INFECTIOUS MICROORGANISMS CONTAMINATE DRINKING WATER? animal waste. Wells and other drinking water sources can be contaminated by storm water run-off from roadways, farms and livestock operations, discharges from sewage treatment plants, or septic system discharges.
Answer:
It causes the medium to move parallel.
Explanation:
