Answer is B. The length of a day on mercury is much longer than Earth
After crystal violet staining, the Gram-positive bacteria may appear dark blue or violet. The cell wall of gram positive bacteria have thick peptidoglycan layer, thus it retains the crystal violet stain compared to gram negative bacteria.
Answer:
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA.
DNA is considered the molecule of life because it contains the instructions that ensure the continuity of life. Employment of DNA to code for protein is the basis of all life on earth.
In all living things, inherited DNA is used to code for amino acids which when joined or linked together in a deliberate specific manner form polypeptides which make up proteins. These proteins are responsible for structure and function of cells.
For example DNA provides information to make four polypeptide (two beta and two alpha ) chains which make up hemoglobin, the protein that functions as the oxygen carrier in red blood cells. In summary,
DNA → protein → trait, and that relationship is the physical basis of life.