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 .
Correct answer: D
A pollen is where male gametes are produced and so the number of chromosomes, as we are talking about gametes, is n. This means that the grain of pollen will only have a copy of each gene, and therefore only one allele for each gene - one S, and one T or t. So, the possible combinations are ST and St.
Translation is a step of the DNA sequence which matches each nitrogen base to its counterpart. In this case, the counterpart of A is U, T is A, G is C and C is G. Given the sequence <span>AAGCTGGGA , the sequence after translation would be UUCGACCCU. Answer is B</span>
The nucleus is responsible for storing dna as well as the instuctions for protein synthesis
