Parasites need a host. If a host tries to get rid of the parasite or kill it, then the parasite either has to leave the body or die.
Answer: true : A pure substance is something that occurs in nature. An element is made up of one type of atom only and cannot be split further. A compound has the combined properties of the elements from which it is made. Atoms show the macro properties of an element.
Explanation:
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.
