Which of the following is a function of the protein called ubiquitin?
a.) it attaches to proteins that are marked for destruction in the cell.
b.) it assists in the removal of introns from a eukaryotic pre-mrna.
c.) it initiates the formation of a transcription complex.
d.) it adds the 3' and 5' caps to eukaryotic pre-mrna.

The correct answer is: a) It attaches to proteins that are marked for destruction in the cell.

Ubiquitin is a regulatory protein of eukaryotic cell with the various of function. The mechanism of its action involves the addition of ubiquitin to a substrate protein (ubiquitination). Ubiquitin regulatory roles are:

•marking thee proteins for degradation via the proteasome,  

•alter the cellular location of proteins,  

•promoting or preventing protein interactions.

surface mining destroys mountain tops, landscapes, forests and wildlife habitats. on top of that, it leads to soil erosion and destruction of agricultural land. the landscape changes can also disrupt river channels and streams, which leads to flooding. which, can destroy plant life and other animals as well.

explanation:

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.