Which activities? I want to say the nucleus as it is the control center of the cell, but this is a vague question.
The injection would be to keep him from getting infections
Limiting factors are resources or other factors in the environment that can lower the population growth rate. Limiting factors include a low food supply and lack of space. Limiting factors can lower birth rates, increase death rates, or lead to emigration.
Chloroplast , cell walls and centriols can be found in plant cell but not in animal cells.
