Genetics is the study of genes, heredity, and genetic variation in living organisms. It is generally considered a field of biology, but it intersects frequently with many of the life sciences and is strongly linked with the study of information systems.he modern working definition of a gene is a portion (or sequence) of DNA that codes for a known cellular function or process (e.g. the function make melanin molecules). A single 'gene' is most similar to a single 'word' in the English language.
Adrenaline is produced in the medulla in the adrenal glands as well as some of the central nervous system's neurons. Within a couple of minutes during a stressful situation, adrenaline is quickly released into the blood, sending impulses to organs to create a specific response. What is the function of adrenaline? Adrenaline triggers the body's fight-or-flight response.
Cortisol, aldosterone and DHEA are produced in the outer layers (known as the cortex) of the adrenal gland whilst adrenaline and noradrenaline are produced in the inner core (known as the medulla)  Each person has two adrenal glands, one above each kidney. Each adrenal is small weighing about 15grams.