Answer:
serotonin
Explanation:
Here is the complete question:. on average, those with the short form of the ________ transporter gene and a history of stressful experiences reported more than average symptoms of depression.
Serotonin is sometimes called the happy chemical, because it contributes to wellbeing and happiness. The scientific name for serotonin is 5-hydroxytryptamine, or 5-HT.
Endocrine system regulation slowly happens but produces long-lasting effects, whereas nervous system regulation quickly takes place with short-term effects.
Endocrine system can regulate many things in the body that control the metabolism. The effect shouldn't be instant, but it should be good for long term effect. Nervous system need a much faster reaction because it responsible for "fight or flight" reaction. A slow nervous system will cause the organism caught by predator easier.
Birds, unlike mammals, do not have separate exits for urine and feces. Both waste products are eliminated simultaneously through the cloaca. While mammals excrete nitrogenous wastes mostly in the form of urea, birds convert it to uric acid or guanine, which reduces water loss in comparison.
