Approximately how much of earth's history occurred during the precambrian super-eon? a. 30% b. 50% c. 75% d. 90%

Which best describes meiosis? a. it produces cells that are identical to the original cell b. it is responsible for the replacement of damaged skin cells c. it is responsible for growth of the organism d. it produces male and female sex cells

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation

How much time has elapsed from the very beginning of "the memior of the conquistador bernal diaz del castillo" to the end? a. castillo's whole life b. a quarter of an hour c. a few weeks d. a decade