Answer:
The barrier functions to regulate the chemical composition of the extracellular fluid surrounding the brain cells.
Explanation:
Blood-brain barrier
It is a very selective semipermeable membrane , hence allow some specific substance to pass via it . This barrier separates the extracellular fluid in the central nervous system and the circulating blood from the brain .
<u>The barrier is composed of the endothelial cells .</u>
Passive diffusion is shown in this system , and allows molecules like the water , glucose , amino acid to pass .
It regulates the chemical composition of the fluid of brain cell .
Answer:
What?
Explanation:
I don't understand the question.
Which structure are you talking about??
Answer:
B. Use the polymerase chain reaction (PCR) to make multiple copies of the DNA.
Explanation:
The scientist is to analyze a small sample of DNA, the most useful step to start this would be first the use of polymerase chain reaction to make various copies of that DNA sample. PCR is essential and quick process that gives a lot of copies within few hours. It uses the sample or target DNA, according to which the primers are designed. Taq polymerase and DNA polymerase are also used in the process, it consist of various cycles in which copies are made. There are three basic steps 'Denaturation', 'annealing', and 'extension'.
Answer:
the answer is dont look it up anymore figure it out
Explanation:
Answer:
B) speciation.
Explanation:
The Galapagos island is known for the different varieties of finches (species of birds) which could be distinguished on the basis of different beak shapes and size.
This is the result of the selection pressure which led to the divergence of the species on the island through a mechanism called adaptive radiation.
Since the adaptive radiation leads to the formation of different species on the same island, the process of formation species is known as the speciation.
Thus, speciation is the correct answer.
