Devise a theory that explains why the most complex animals only reproduce sexually

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

Why did mendel use pea plants in his experiments? a. they have no alleles. b. they are haploid organisms. c. they reproduce quickly. d. they are all male.

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex