Have all species on Earth evolved from a common ancestor?

Why does meiosis produce cells with half the chromosomes? o a. most of the chromosomes are not necessary to keep an organism alive. b. a gamete needs only half the number of chromosomes because two gametes join together. o c. it makes the gametes easier to move around in the organism. o d. it is faster to produce gametes with fewer chromosomes.

What is the correct trna sequence that would match the following mrna sequence. gcgaua

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this