Achemical substance made by glands in the endocrine system that travel through the bloodstream and affects cells and tissues throughout the body ?

Answers: Hormones

Explanation:

A collection of all the glands and groups of cells that secrete chemical messengers that function in regulating the growth, development, and homeostasis of the body is termed as the endocrine system.The chemical messengers of the endocrine system are known as hormones.  These hormones are a type of signaling molecules produced by the glands and cells of the endocrine system and they are carried by the blood to distant organs in the body.The organs in the body that carry receptors for these hormones are known as the target organs, and the hormones affect the body's physiology by exerting their effect on these target organs.

The answer is observations and interpreting.

C. a mature ovule of a plant.