Answer:
I think B is baby teeth and A is permanent teeth
a) Baby teeth doesn't fall on schedule and permanent teeth come in behind them this results is two rows of teeths.
The mitochondria is the powerhouse of the cell. on a serious note, The most prominent roles of mitochondria are to produce the energy currency of the cell through respiration, and to regulate cellular metabolism
B.haploid cells are formed
Mutation. this happens when a cell copies its DNA to divide. its more common than you may think, a "typo" occurs every 100, 000 or so nucleotides, thats about 120, 000 "typos" every time a cell divides.