The correct option is D.
A virus refers to an infectious micro organism that is made up of nucleic acid molecule that is enclosed within a protein coat. Viruses are only able to reproduce and multiply when they come in contact with living cells, in the absence of living cells they remain dormant and they do not show any sign of been a living thing. The nuclei acid molecule of a virus can be in form of a DNA molecule or a RNA molecule.
Answer:
The sister chromatids are identical to one another and are attached to each other by proteins called cohesins. They are formed.
Explanation:
I think it’s because you have trouble breathing
1 presence of mind
2 disscussion
3 intelligent
Answer: simple diffusion, the alveoli
Explanation: The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion.
