The human mouth has a plethora of bacteria species. why is there so much variety of bacteria in the mouth?

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun

Plz ! what does it mean for an allele to be dominant?

If t=tall and t=short what will be the physical appearance of the offspring the cross below? a. some will be tall and some will be short b. they will all be tall c. they will all be short d. they will be medium height