Hey there!
The purpose of guard cells is to control the opening and closing of the Stomata, keeping it the correct width, or size.
Therefore, your correct answer would be Option 3, control the size of the Stomata.
Hope this helps!
Answer:
Energy can change from one type to another.
there is mostly billions of amount of water from raindrops each day i think.
If You want a EXACT number i'll say, 1,100.
If you go on mc3.edu/admissions/applying-to-mccc/testing-and-assessment/assets/biology-placement-test.pdf page 11 it will tell you all the answers to your questions....
If the shape of this unknown skull is long and skinny at the cheekbones, then it is most likely an Australopithecus afarensis one