Ais a substance or a cgemical compound required by the animal for these productive purposes

A nutrient is a substance or a chemical compound required by the animal for these productive purposes .

Explanation:

Nutrients are essential compounds and macromolecules needed for a variety of metabolic processes.  Animals show heterotrophic nutrition by consuming organic matter like lipids, fats, and proteins.

Food provides essential vitamins, amino acids and minerals that are used as cofactors and coenzymes in chemical reactions.

For example, animals use carbohydrates as fuel for all metabolic processes.

C6H12O6+ 6 O2 → 6 CO2 + 6 H2O + ≅38 ATP

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