In times of stress the sympathetic nervous system stimulates the adrenal medulla which then secretes catecholamines. The catecholamines includes; Dopamine, epinephrine and norepinephrine. Catecholamines are made by nerve tissue, the brain, and the adrenal glands. They help the body respond to stress or fright and prepare the body for "fight or flight" reactions.
Endocytosis is the process by which Bulky Molecules enter the cell.
Explanation:
- Endocytosis is the process by which eukaryotic cells take up large molecules into their cytoplasm.
- The large molecules that cannot enter the cell through protein channels of the plasma membrane are carried into the cell in membrane bound vessicles.
- The vessicles are formed by progressive invagination of the cell membrane and then pinching off after the molecule is trapped.
- Endocytosis has been classified as phagocytosis (cell eating) and pinnocytosis(cell drinking).
Answer:
e) An agent, such as a plasmid, used to transfer DNA from an in vitro solution into a living cell.
Explanation:
A cloning vector is a naked DNA that can be maintained and into which a foreign DNA can be inserted. A vector needs to be small in size, have restriction sites for endonuclease enzymes and the ability to multiply and express itself at a high rate, without disrupting the host cells machinery. Perfect cloning vectors are DNA molecules from viruses, plasmids and bacterial species such as E.Coli.
The scientific method
a process used by scientist to investigate questions. It is a series of steps that allow scientist to meaningful experiments in an organized way.1)observe and ask questions. 2)form hypothesis.3)plan an experiment.4)conduct(do) the experiment 5)draw conclusions
