Halie Knows: Mitosis Versus Meiosis
January 15, 2019
Mitosis and Meiosis sound very similar, but while they share some similar concepts they are two different biological terms. What is Mitosis? Mitosis is cell division creating two “daughter” cells. Daughter cells have the same number of chromosomes and the same kind of chromosomes as the parent cell. What is Meiosis? Meiosis is creating four “daughter” cells that have half of the chromosomes as the parent cell.
While Mitosis and Meiosis both create daughter cells they make two different kinds. Mitosis creates diploid cells or cells that have 23 chromosomes. While meiosis makes haploid cells or gametes which are your reproductive cells such as sperm in males and eggs in females.
Mitosis exists in six different stages each stage doing something different inside of the cell undergoing mitosis.
- Interphase: This stage is when the cell is only preparing for Mitosis or Meiosis(Interphase happens in both). This is also where a cell spends most of its life.
- Prophase: Prophase is the “first” stage where the nuclear membrane and the nucleus disappear, chromosomes condense and the mitotic spindles form.
- Metaphase: This stage is when the duplicated chromosomes line up at the center of the cell. Fun fact this is called the metaphase plate.
- Anaphase: Anaphase is when the duplicated chromosomes separate into two identical groups and move towards opposite ends of the cell.
- Telophase: This is the second to last stage where membranes form around the two groups of chromosomes at different ends to produce the nuclei in the daughter cells. The nuclei or the nucleus is the control center of a cell containing the DNA blueprints for the cell.
- Cytokinesis: Cytokinesis is the final stage where the spindles disappear and the cytoplasm divides.
Meiosis is like Mitosis but with some clear differences between the two. Meiosis even shares similar stages with Mitosis with its differences present.
- Interphase: Just like Mitosis cells undergoing Meiosis must start in interphase where it prepares for Meiosis.
- Prophase One: Prophase in Meiosis still has chromosomes condensing but they also pair up. Each chromosome alines with their homologue partner so that the two can line up correctly. During this stage crossing over occurs as well.
- Metaphase One: After crossing over the spindles catch the chromosomes and move them to the center of the cell. Unlike Mitosis homologous pairs line up at the center instead of individual chromosomes. Also when they line up the order is random allowing gametes with different sets of homologous.
- Anaphase One: The homologues are pulled apart and moved to different sides of the cell-like Mitosis but the sister chromatids stay together.
- Telophase One: Just like Mitosis the chromosomes arrive at different ends of the cell. Unlike Mitosis though most cells do not go under Cytokinesis since Meiosis has two rounds of division. Although not all cells do this.
Meiosis happens in two stages unlike Mitosis because cells undergo their own “tiny Mitosis’ so they can be divided in half.
- Prophase Two: Starts with chromosomes condensing and the nuclear envelope breaks down if needed. The centrosomes move apart and the spindle starts to form and capture chromosomes.
- Metaphase Two: Just like Metaphase one the chromosomes individually line up along the center of the cell or the metaphase plate.
- Anaphase Two: Unlike Anaphase One sister chromatids separate and are pulled to different sides instead of staying together.
- Telophase Two: During Telophase Two nuclear membranes form around each set of chromosomes, and the chromosomes decondense down, then Cytokinesis takes place.
- Cytokinesis: Just like in Mitosis Cytokinesis splits the chromosomes sets into new cells forming the product of Meiosis four haploid cells.
Mitosis and Meiosis both have ways of dividing cells Meiosis just has one extra step before the division. They both create different kinds of cells with creating Mitosis diploid cells and with Meiosis creating haploid cells or cells that have half the number of chromosomes.
- Homologue: BIOLOGY
(of chromosomes) pairing at meiosis and having the same structural features and pattern of genes.
- Crossing over: GENETICS
the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring.
- Sister Chromatids: Sister Chromatids are two identical copies of the same chromosome formed by DNA replication, attached to each other by a structure called the centromere.
For the definitions of Homologue and Crossing over.
For the definition of Sister Chromatids.
For info involving Meiosis and its two stages.
For info involving Mitosis and its one stage.
More/fun info about Mitosis/Cytokinesis