Which of the following is an example of a prerequisite? The student must follow a medical doctor around in a job shadow arrangement before they can apply to medical school.
The veterinary student must study anatomy of felines before they study anatomy of canines.
The student must complete basic Biology and intermediate Biology before they can take the course on advanced Biology.
The student should complete the MCATs before she/he decides which specialty to go into.

since you have not provided the options here i   am going to give you general overview about hormone.hormone are actually the part of endocrine system in our body and produced by the endocrine glands. the hormones act like a chemical messenger   within human body. once produce by the glands they   travel through the blood stream and reach at specific or target tissue and organs   which result in control of our body function. the hormones are specific in their work and work on only the targeted tissue or organ   . with the of hormone endocrine system regulate the heart rate , metabolism, our mood and   growth as well as the development and even the sleeping cycle etc. they actually are the messenger for body cell and organs .

myth: mosquito bites transmit hiv. & shaking hands often transmits hiv. & oral sex never transmits hiv.

fact: breastfeeding can transmit hiv. & unprotected sex transmits hiv.