Question

explain why meiosis must begin with a diploid cell, while mitosis is not so restricted

Answer 1

Diploid means two copies of each chromosome. Meiosis is the division of cells that results in two sex cells (gametes). Each gamete needs one chromosome, so the parent cell needs to have two copies. In mitosis, the chromosomes replicate and divide, so each daughter cell gets the same two chromosomes as the parent cell.

Answer 2

In meiosis, there are two divisions, so there need to be two original chromosomes that divide in order that by the second division, each of the four daughter cells are haploid (have one copy of each chromosome)