True or false each organ in the body is part of a(n) organ system performing a major function?

*will mark brainliest to first correct answer* photosynthesis led to increasing levels during the later proterozoic eon? a. oxygen b. water c. carbon dioxide d. none of the above

Nucleic acid certain protein cell membranes certain carbohydrates

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?