<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
Answer:
The genetic code consists of <u>three</u> letter “words.”
Explanation:
I'm assuming this was what you're looking for. These "words" are known as codons: for example, AUG stands for the methionine amino acid, so that triplet of nucleotide bases leads to the Met amino acid being added to the final protein.
Decrease in the tree population can damage the environment.
