Answer:
Explanation: Guard cells in the plants prevent water loss from it in cases of soil dryness or high temperature by closing themselves. If this does not happen, water will keep leaving the plant by the process of transpiration in these harsh conditions and the plant will not have the important medium for the homeostasis process to continue.
Answer AND Explanation:
There is a large number of biochemical reactions taking place in a cell at any given time. Enzymes being biological catalysts control these reactions and regulate them so that they proceed at a pace that is suitable for sustaining life. Thus enzymes regulate cellular activities. Enzymes also ensure that only the required reactions take place and progress to their appropriate extent.
There is evidence that evolution occurred, but nothing is proved for sure. I'm sure you can find the information if you search it on the internet. Sorry, this probably won't be helpful for your question, but please don't hate. I just wanted to tell you that you might want to think about the possibility that there wasn't a big bang, and everything spontaneously appeared, or that everything evolved from a single bacteria or whatever, or that the earth is billions of years old. If you look into it, lots of that evidence isn't even lined up correctly. I believe that there is a creator, who carefully designed everything with love. I know it sounds cheesy, but this creator, or designer who made all of us, is the reason we even celebrate Christmas. Anyway, thanks for reading this, God bless.