What is an ecosystem? a. It is one species that lives in a given area.
b. It is a single plant and a single animal that live in a given area.
c. It is the members of the same species in an area.
d. It is a community of plants, animals, and their physical surroundings.

d

Explanation:

All the other ones are talking about one species or one plant Whereas D, includes all of them.

idk

explanation:

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