30 chest compressions to 2 rescue breaths
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
Answer:
The relationship between snails and elodea is symbiotic in that the snail eats algae and produces carbon dioxide. The elodea takes in the carbon dioxide and, through photosynthesis, creates oxygen, which the snail and every living thing in the tank uses to breathe.
Explanation:
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