White blood cells protect the human body against invaders and infectious diseases. what organelles do you think play a critical role in them doing their job? Define "organelle" in your own words.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u