Answer:
18 is the nuclesus, 20 is the smooth endoplasmic reticulum and 21 is the golgi apparatus and 19 is the microtubes and 17 is the vacules.
Explanation:
A constant is something that is kept the same throughout the course of a experiment. So I would guess C) because they are not doing anything special. If it’s not C then it is A. :)
It should be translation.
For question 3, it would not leak through the whole sandwich because the cell membrane is thick