After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Answer:
B
Explanation:
I would say this because the pulmonary circulation only transports deoxygenated blood. And this blood gets transported to the lungs so the lungs can absorb oxygen and release carbon dioxide. I am not sure about this one though. This is what I think.
<span>it decomposes dead organisms, fixes nitrogen, and can break down some petroleum. and it can infect something and decrease its chance of survival.
Bacteria plays an important role in the environment. It decomposes dead organisms, fixes nitrogen, and </span>can break down some petroleum. It can also infect 'something' and decrease its chance of survival.
<span>C. by making and breaking the chemical bonds in organic compounds. Don't worry I'm a science geek. </span>
There are living organisms that do these processes alongside one another to sustain a balanced cycle.
