the spliting of the cells

unit 6. by christian smith, and aaron darling

MITOSIS

Mitosis is the process of one diploid cell divides into two diploid daughter cell which are identical to the parent.


  • the cells must duplicate their DNA during s-phase so the daughter cells can have a complete set of DNA
  • the cells only spends 10% of their time during mitosis
  • many phases during Mitosis, these phases occur in this order. Prophase, Metaphase, Annephase, Telophase, and Cytokinesis
  1. Prophase: the DNA condenses into chromosomes. The nucleus starts to fade away
  2. Metaphase: The centrioles travels to opposite ends of the cell and the chromosomes line up in the middle of the cell. the spindle fibers start to latch on to the chromosomes
  3. Annephase: the centrioles use the spindle to split the chromosomes in half and pulls them to the opposite ends of the cell
  4. Telophase the cells start to form new nucleus around each of the different sets of chromosomes. also the cell start to pinch in half
  5. Cytokinesis: the cell completely splits and the 2 cells are now identical to the parent cell.
  • mitosis makes somatic cells also known as body cells.

Meosis

  • Meosis is where a cells splits into 4 genetically different cells
  • Meosis goes though similar phases as mitosis, but meosis dose some really important extra steps
Here are the phases of meosis, i will only say what is different for each for meosis however.


  1. Prophase 1
  2. metaphase 1: crossing over happens in this phase.
  3. Telophase 1
  4. cytokinesis
  5. Prophase 2: the divideing of the cell starts again.( however the cell did not replicate it dna this time)
  6. Metaphase 2
  7. Anaphase 2
  8. Telophase 2
  9. cycokinis
  • meiosis makes gamets, such as sperm and egg.
  • after this, when the egg and the sperm meet, the sperm fertilizes the egg and creates a zygote with both the sperm's and egg's DNA

Crossing over

This is a fundumental part of Meosis. this is what causes the gentic variasion. As you know, this happens during prophase 1. the cromosomes trade peaces of it self with its sister cromosomes (wich are just cromosomes wich correspond with each other) to cause a mix of its DNA.

Non-disjution

Non-disjution is where the cromosomes fail to split corectly duiruing cell divison. this can be a huge proplem because this can cause missing chromosomes from gametes, or the opposite, a surplus. this can cause many problems such as turners syndrome or down syndrome. but most commonly is death will still a fetus.