Answer: A
Explanation: gravitation keeps moon in circular orbit.
Without gravitational force Moon would move in
Linear path.
Answer:
secrete a cytokine that triggers apoptosis
Explanation:
Cytotoxic T cells secrete granzymes and perforins when targeting cells. Additionally they secrete cytokines such as IFN-, TNF-α and TNF-β that act to activate macrophages and help kill infected cells.
Cells depend on the body environment to live and function. Homeostasis<span> keeps the body environment under control which keeps the conditions right for the cells to live and function. Not having the right body conditions can result in certain processes and proteins won't function properly.</span>
