The sentence which is true or a fact about the virus is the sentence in letter B. Viruses can reproduce only within other cells. <span>Viruses are intracellular obligate parasites they can not replicate or express the genes with out living host. </span>
<span>viruses are acellular so they have to rely on host cellular machinery for reproduction. </span>
<span>viruses doesnot contain any enzymes for reproduction</span>
Artificial Selection? I'm just guessing
Answer:
Ratio = 
Explanation:
Side of a cube, a = 20 µm

The surface area of a cube, A = 6a² (a is side of the cube)
The volume of a cube, V = a³
The ratio of the surface to volume ratio of the cell will be given by :

So, the ratio of the surface to volume ratio of the cell
.
Answer:
A sucessão primária ocorre em ambientes estéreis, onde não havia vestígios de organismos vivos que a ocupassem antes. Esse ambiente pode ser um local vulcânico em que a lava derretida destruiu o meio ambiente ou foi causada por dunas. A comunidade inicial de organismos para habitar esses ambientes é conhecida como sucessores primários ou colonizadores primáriosrimários
Explanation:
Primary colonisers initiate primary succession as such they are important to the future of such environments. They are though breeds of organisms that make use of scarce resources to survive in harsh environments. Without their ability to survive, there will be little or no way other forms of succession can take place. Reasons, why they may not persist, maybe too much stress imposed on them by the environment and above all their inability to compete when other successors come on board.