B. essential
We cannot store up amino acids on our body, but we can have amino acids through consumption of food. These amino acids of which the body cannot make is called as essential amino acids.
The action by which a fluid enters the microhematocrit tube because of the attraction between the fluid and the tube is called capillary action.
You have to have both the pL promoter as well as a second system of the cI repressor which controls the pL promoter.
When the cI repressor is expressed it will bind onto the operator region of the pL promoter and prevent expression.
When the cI repressor is not expressed it can't bind to its operator and the pL promoter (which is very strong) can express whatever gene it is upstream of.
So you need to have both for transcriptional control. you don't need the rest of the phage!
Answer:
The hypothalamus is located on the undersurface of the brain. It lies just below the thalamus and above the pituitary gland, to which it is attached by a stalk. It is an extremely complex part of the brain containing many regions with highly specialised functions.