Question

What environmental factor seems most critical to cellular respiration?

Answer 1

Water is one of the most important factors affecting cellular respiration.

Water is an essential component of cellular respiration and without it, the process cannot proceed further. For the activation of enzymes, water is considered an essential factor. The low water content in the plant can restrict its growth as well as can cause the plant to wilt.

Answer 2

Cellular respiration can be affected by several factors, among which we have to.
a, Breathing increases as temperatures increase and decrease as temperatures fall.
b. Oxygen is required for aerobic respiration to occur. If oxygen levels are reduced in the atmosphere, breathing slows down.
c. Soils saturated with water lack oxygen. In the absence of oxygen, breathing does not occur.
d. In low light conditions, plants produce less carbohydrates. Low levels of carbohydrates, in turn, mean low respiration rates.  
e. The stage of growth and the age of the plant influence the respiration rate necessary to maintain the processes of life. Young plants that grow actively tend to have a higher rate of respiration.  
f. Water is essential for cellular respiration and photosynthesis. Without water, the enzymatic activity stops. The plant essentially stops growing The lack of available water during drought conditions can cause the arrest of respiration. 
Of all these factors, it could be said that the most important and the most critical is precisely the latter, that is, water.