Answer:
Enzyme- Peptidase/protease
Explanation:
According to this question, a student is conducting an experiment to determine the roles of molecules in metabolic processes such as digestion. Based on what she found out that the molecule, which itself can be broken down into amino acids, can also break down proteins into amino acids, this suggests that the molecule being described is a PROTEOLYTIC ENZYME.
This is because an enzyme is made up of proteins which can be denatured or broken down into its simplest unit (amino acids) and also, a substance that breaks down amino acid is said to be PROTEOLYTIC.
However, another observation that the molecule is found in high concentrations in the small intestine was made, hence, the enzyme is a PEPTIDASE OR PROTEASE, which are secreted into the small intestine by the pancreas to aid digestion of proteins.
I'll choose Golden Retrievers:
These dogs where created for duck-hunters. Their purpose was to go catch the ducks that fell on the lake/river once they were shot by the hunter - here we see how they serve (or actually served) men.
Nowadays, Golden Retrievers are known to like water a lot, and to be very playful with it - and here is where we see a genetic adaptation. They needed to be in water, and were modified to like it.
Hope it helped,
BioTeacher101
Answer: The fight-or-flight response is most clearly associated with the release of epinephrine into the bloodstream.
Any physiological reaction occurring due to something which frightens physically or mentally is fight-or-flight response. In order to produce the fight-or-flight response the hypothalamus activation of the adrenal cortical system and sympathetic nervous system takes place. On receiving the signal from hypothalamus the sympathetic nervous system makes the actions of body speed up or gets tensed and body is in an alert condition.
The impulses are sent by the sympathetic nervous system to the smooth muscles and also glands. As a response to it epinephrine or adrenaline and the norepinephrine or noradrenaline is released by the adrenal medulla in the bloodstream. These stress hormones thus bring about changes in the body such as increase in blood pressure and heart rate.