<span>Answer:
Vaccine generates a population of plasma cells that increase the concentration of antibody in the bloodstream.
Explanation:
Vaccines are inactive or non functional infectious agents enter into the body in order to generate antibody against such agents In future if virus or bacteria that is resemble to the structure of already injected agents attack on human body. The immune system get alert and antibody which are already produced attack on them and prevent them from causing disease.</span>
Answer: A
Explanation:
Well the other answers wouldn't affect the population that much. But of course if a predator's population is overgrowing that means they are gonna kill too much of the prey before they have enough time to reproduce.
Answer:
Oxygen
Explanation:
The circulatory system gets oxygen from the respriatory system and circulates it throughout the body.
The more closely related the organisms, the more similar the bond structures. Many mammals , for example, have similar limb structures. The rabbit is similar to the human arm, with a large upper bone "arm" (the arm in humans) and a lower part of two bones, a larger bone on one side (the radius in humans) and a smaller bone on the other side (the ulna). These species also have a collection of smaller bones in the wrist area (called carpal bones in humans) that lead to the "fingers" or phalanges