Melatonin is secreted principally by the pineal gland and mainly at nighttime. The primary physiological function is to convey information of the daily cycle of light and darkness to the body.
Handedness. ...
Freckles. ...
Curly hair. ...
C) Drug
A drug is a chemical substance used to treat, prevent, or diagnose a disease or alter one or more functions of the body. Antibiotics, Analgesics, and antihistamine are all not able to do all of the following.
Age, race, gender, heredity ( heart disease, depression, dementia, diabetes, low blood pressure)