Cell Division (Meiosis) Flashcards
Process where a single celled divide twice to produce 4 cells containing half of the original amount of genetic information. These cells are our sex cells.
Meiosis
Single set of chromosomes (gametocytes)
Haploid or Reproductive cells
DNA in the cell is copied resulting into 2 identical full sets of chromosomes
Interphase
The chromosomes pair up so that both copies of chromosome 1 and 2 are together. Exchange bits of DNA in a process crossing over
Prophase I
The chromosome pairs line up next to each other along the center.
Metaphase I
The pair of chromosomes are then pulled apart by the meiotic spindle. Note that sisters chromatids stay together
Anaphase I
The chromosomes complete their move to the opposite poles of the cell. A membrane forms around each set of chromosomes to create 2 new nuclei. The single cell then pinches in the middle to form 2 separate daughter cell each containing a full set of chromosomes within a nucleus.
Telophase I/cytokinesis
Each of the 2 daughter cells the chromosomes condense again into visible x shaped structures. The centrioles duplicates and meiotic spindle forms again
Prophase II
Each pair of sister chromatids line up en to end akong the equator of the cell
Metophase II
The sister chromatids are then pulled to opposite poles, separating chromatids to individual chromosomes
Anaphase II
A membrane forms around each set of chromosomes to create 2 new cell nuclei
Telophase II/Cytokinesis
Benefit of mitosis
Creates identical copies of the original cells
Benefit of meiosis
Continually reshuffles the genes resulting into a great variety of offspring. Because everyone’s DNA isn’t exactly alike.
Disadvantage of mitosis
If a new disease comes along every single organism/plant will be wiped out because if it is unable to fight that disease no one can.
Disadvantage of meiosis
An organism cannot reproduce all by itself, but must find another organism.
