Question

What happens during meiosis?a) Chromosome pairs separate to form new sex cells, increasing genetic variation.b) Each sex cell copies itself to form four new sex cells that are all identicalc) Each sex cell loses half of its chromosomes, decreasing genetic variationd) Chromosome pairs remain together when new sex cells are formed, maintaining the same level of genetic variation

Answer 1

During meiosis, chromosome pairs separate and form new sex cells, increasing genetic variation. This process is divided into two phases: Meiosis I with crossing-over and Meiosis II, the separation of chromatids, resulting in four unique haploid cells.

Step-by-step explanation:

What happens during meiosis? The correct answer is a) Chromosome pairs separate to form new sex cells, increasing genetic variation. Meiosis is a cell division process that reduces the chromosome number by half and produces gametes, otherwise known as sex cells. During the first phase, Meiosis I, homologous chromosomes pair up and exchange genetic material in a process known as crossing-over, which only occurs during prophase I. This crossover increases genetic variation by mixing the genetic information from the two parents.

Afterward, these homologous chromosome pairs separate and go into two distinct cells. In the second phase, Meiosis II, which resembles a typical mitotic division, the sister chromatids (which became visible after DNA replication during the S-phase) are separated into individual chromosomes. The end result of meiosis is four genetically unique haploid cells, each with half the number of chromosomes of the original cell.

Thus, the statement that each sex cell loses half of its chromosomes, thus increasing genetic variation, is the most accurate. This process is essential for sexual reproduction as it ensures that when gametes fuse during fertilization, the resulting zygote has the correct number of chromosomes.

Answer 2

Meiosis is a reductional division, which involves two rounds of division and results in four haploid cells.

During meiosis I, the homologous chromosomes pair and recombine, and after that, they are separated into two haploid cells.

During meiosis II, the sister chromatids are separated, and a total of four haploid cells are produced.

Of the options, the sentence that better describes what happens in meiosis is A, chromosome pairs separate to form new sex cells, increasing genetic variation.