Why is the nucleus called the control center of the cell?

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

The fascicles of the deltoid are ; the fascicles of the pectoralis parallel; bipennate fusiform; unipennate multipennate; triangular bipennate; fusiform

Give two examples of what would occur if one of the pairs did not match or had an extra chromosomes. explain how this might occur, and if it would be dangerous to the individual. fast.