Question

How do the results of meiosis and mitosis differ in terms of chromosome numbers? Fill in the diagrams with the appropriate chromosome number (total number of chromosomes and/or sister chromatids!) by assuming that each original cell (at the top of the diagram) represents a human cell with a diploid number of chromosomes in G2 stage of the cell cycle. mitosis meiosis O first meiotic division first meiotic division 2nd meiotic division O OO O

Answer 1

In mitosis, the genetic material (DNA) in a cell is duplicated and divided equally between two cells...The mitotic cell cycle is initiated by the presence of certain growth factors or other signals that indicate that the production of new cells is needed. Somatic cells of the body replicate by mitosis..Mitosis is necessary to replace dead cells, damaged cells, or cells that have short life spans.

Meiosis is the process by which gametes (sex cells) are generated in organisms that reproduce sexually. Gametes are produced in male and female gonads and contain one-half the number of chromosomes as the original cell. New gene combinations are introduced in a population through the genetic recombination that occurs during meiosis. Thus, unlike the two genetically identical cells produced in mitosis, the meiotic cell cycle produces four cells that are genetically different.

Two daughter cells are produced after mitosis and cytoplasmic division, while four daughter cells are produced after meiosis.

Daughter cells resulting from mitosis are diploid, while those resulting from meiosis are haploid.

Daughter cells that are the product of mitosis are genetically identical. Daughter cells produced after meiosis are genetically diverse.

Tetrad formation occurs in meiosis but not mitosis.

Chromosome Alignment in Metaphase

Mitosis: Sister chromatids (duplicated chromosome comprised of two identical chromosomes connected at the centromere region) align at the metaphase plate (a plane that is equally distant from the two cell poles).....Meiosis: Tetrads (homologous chromosome pairs) align at the metaphase plate in metaphase I.

. Chromosome Separation

Mitosis: During anaphase, sister chromatids separate and begin migrating centromere first toward opposite poles of the cell. A separated sister chromatid becomes known as daughter chromosome and is considered a full chromosome.......Meiosis: Homologous chromosomes migrate toward opposite poles of the cell during anaphase I. Sister chromatids do not separate in anaphase I

In humans, each mitotic daughter cell would be a diploid cell containing 46 chromosomes. ...Each meiotic daughter cell would be haploid containing 23 chromosomes.