Answer:
it has four valence electrons
Explanation:
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.
Answer:
The endosymbiotic theory states that some of the organelles in eukaryotic cells were once prokaryotic microbes. Mitochondria and chloroplasts are the same size as prokaryotic cells and divide by binary fission. Mitochondria and chloroplasts have their own DNA which is circular, not linear.
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