Mitosis and Meiosis by

What is Mitosis?

dieselgurl8_ — 2023-11-20 01:58:31 UTC

Mitosis is a type of cellular division where the result is two daughter cells. These cells each have the same number of chromosomes as the parent cells.

What is Meiosis?

dieselgurl8_ — 2023-11-20 01:59:11 UTC

Meiosis is a type of cellular division where the number of chromosomes are split in half and form gametes, sperm and egg cells, which each contain their own unique diversity.

“Meiosis is important for creating genomic diversity in a species. It accomplishes this primarily through 2 processes: independent assortment and crossing over (recombination).” Gottlieb, S. F. (2023, August 14).

Steps of Mitosis

dieselgurl8_ — 2023-11-20 02:07:05 UTC

Interphase: During this phase, the cell prepares for division. In order to do so, the DNA is duplicated.
Prophase: In this phase, the chromosomes condense and become visable. The breakdown of nuclear membranes begin.
Metaphase: At the cell’s equator chromosomes align.
Anaphase: Dupltcated chromosomes also known as sister chromatids are seperated toward opposite poles of the cell.
Telophase: During this phase the chromatids reach the poles and de-condense. The nuclear membranes reform around each set of chromosomes.
Cytokinesis: In this final phase, the cells cytoplasm divides and as a result, two genetically identical daughter cells are created.

Steps of Meiosis

dieselgurl8_ — 2023-11-20 02:15:26 UTC

Meiosis I:

Prophase I: In prophase I, chromosomes condense and homologous chromosomes exchange genetic material through crossing over.
Metaphase I: In this phase pairs of homologous chromosomes align at the cell’s equator.
Anaphase I: In Anaphase I, Homologous chromosomes are then seperated, sister chromatids stay attached to one another.
Telophase I: In this phase, chromosomes reach the poles, cells divide into two daughter cells, each containing half the chromosome number.

Meiosis II:
1. Prophase II: Here, chromosomes condense again within the two daughter cells.
2. Metaphase II: In Metaphase II, the chromosomes align at the cell’s equator.
3. Anaphase II: The sister chromatids seperate.
4. Telophase II: In this stage, the chromatids reach the poles, cells divide again, and four genetically unique haploid daughter cells are created.

How does the behavior of chromosomes during meiosis generate variation and explain Mendel’s law of independent assortment?

dieselgurl8_ — 2023-11-20 02:16:49 UTC

The behavior of chromosomes during meiosis generates variation through a couple of different processes. Independent assortment and crossing over. Independent assortment is when there is a random distribution of homologous chromosomes to daughter cells. Crossing over is when there is an exchange of genetic material between homologous chromosomes during Prophase I. This variability is the basis for Mendel’s Law of Independent Assortment, which states, “that genes do not influence each other with regard to the sorting of alleles into gametes: every possible combination of alleles for every gene is equally likely to occur” Libretexts. (2022, June 9).

References:

dieselgurl8_ — 2023-11-20 02:25:09 UTC

Gottlieb, S. F. (2023, August 14). Genetics, meiosis - statpearls - NCBI bookshelf. National Library of Medicine. https://www.ncbi.nlm.nih.gov/books/NBK482462/

Libretexts. (2022, June 9). 12.3D: Mendel’s Law of Independent Assortment. Biology LibreTexts. https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biology_(Boundless)/12%3A_Mendel%27s_Experiments_and_Heredity/12.03%3A_Laws_of_Inheritance/12.3D%3A_Mendels_Law_of_Independent_Assortment

Aryal, S. (2023, September 22). Mitosis vs. meiosis: 32 major key differences. Microbe Notes. https://microbenotes.com/differences-between-mitosis-and-meiosis/