8) is b.
im not sure if this is right though
18) is d
Answer: Asexual
Explanation: Since only one parent is needed, asexual reproduction is more beneficial. It is a "simpler" (in terms of not needing two mates to fornicate) and causes species to reproduce at a faster rate
Answer:
B. it expands and shrinks in the soil
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.