I believe the answer is all of the above
1) Enzyme activity
2) Cell to cell recognition
3) Cell signalling
4) Transport Materials.
Hope this helps! :)
A. Listen. I believe listening is a conscious action. If you are focused on another action (talkin) you can't listen at the same time.
Because every cell have some life span after this they become older and damage, so cells divide to replace old and damage cells.
