One type of density change is mass over volume.
It is mRNA because RNA, which stands for ribonucleic acid, is a polymeric molecule made up of one or more nucleotides. ... During the process known as transcription, a RNA copy of a segment of DNA, or messenger RNA (mRNA), is made. This strand of RNA can then be read by a ribosome to form a protein.
Answer: B. Closed
In a closed circulatory system is the one in which the blood is circulated to all the parts of the body of the organism through vessels of different length and width. In this system the blood is pumped from the heart through blood vessels where it is transported to different organs and cells of the body instead of filling up the body cavity.
Overpopulation can lead to overuse of resources, extreme pollution, war, plague, starvation, and many more serious world problems
