Based on cell theory, why is a virus considered non-living? a) a virus does not have a nucleus. b) a virus does not contain genetic material. c) a virus is too small to be considered a cell. eliminate d) a virus cannot reproduce itself without a host cell.

The correct answer option is D) A virus cannot reproduce itself without a host cell.

Explanation:

Viruses cannot keep themselves in a stable state as they are not made out of cells they don’t grow so they cannot make their own energy.

Though these viruses do replicate and adapt to their environment but they are are more like androids than real living organisms.  

They lack the ability of reproduction without the help of a host cell and do not use the typical cell division approach to replicate.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.