The cell cycle must be regulated in a multicellular organism in order to
a. maintain the proper cell number in tissues
b. activate cell division when repair of a tissue is needed
c. halt cell division when repair of a tissue is complete
d. prevent cancer
e. all of the above

The correct answer is E. all of the above

Explanation:

The cell cycle has several checkpoints that helps in the regulation of the cell cycle. Cell cycle regulation is important because if the cell cycle is not regulated then the cell will constantly divide which will be a waste of energy and an abnormal increase in the number of cells can do damage to the tissue. So regulation is important to maintain a proper cell number in the tissue.

Cell division helps in repairing the damaged tissue, therefore, cell division must be stopped after tissue is repaired and regulation is also important to prevent cancer because cell division stops when the mutation occurs in the cell's genetic material. Therefore the correct answer is E.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

the answer will be a) proteins i believe