Posts Tagged ‘rob23mitosis’

Modelling Mitosis

  1. Prophase
  • Interphase: Interphase is the longest cell cycle and it is when your cell performs normal functions and grows. During the interphase, the cell receives nutrients and creates and uses protein. An example of interphase is an intestinal lining cell absorbing nutrients.

 

 

 

 

  • Early Prophase: In the process of early prophase the nucleolus disappears and spindle fibres form. the spindle is a structure which is made up of microtubules. This is part of the cell’s skeleton. Its task is to organize the chromosomes and move them around during mitosis. In this phase, the chromosomes also start to condense making it easier to pull apart in later stages.

 

 

 

 

  • Late Prophase: The mitotic spindle in this phase begins to organize all the chromosomes. The chromosomes from the previous stage have become even more condensed making them compact. The spindle fibres attach to centromeres of chromosomes. The spindle grows bigger and some of the microtubules start to capture chromosomes.

 

 

 

  1. Metaphase
  • This is the stage where all the chromosomes have been captured and line up at the middle of the cell, ready to divide. All the chromosomes align on the Metaphase Plate. In this stage, two Kinetochores of each chromosome attach to microtubules from opposite spindle poles.
  • After all this there is another important step. The spindle checkpoint makes sure to check if all the chromosomes are on the metaphase plate with their Kinetochores attached to the microtubules. This is extra precaution so that the two daughter cells separate in the next stage.

 

 

  1. Anaphase
  • The sister chromatids are separated from each other and are pulled to the opposite ends of the cell. The protein that holds the sister chromatids is broken which allows them to depart from each other. Each is now their own chromosome and settle at the opposite ends of a cell.

 

 

 

 

 

  1. Telophase
  • This is the final stage of the Mitosis process. In tis stage, spindle fibres disappear and a nuclear membrane forms around each separated set of chromosomes.
  • The cell is nearly done dividing and it starts going back to its normal structure as Cytokinesis.
  • In this step, two new nuclei are formed. the nuclei is obtained from the two different chromosomes. The nucleoli and nuclear membrane also reappear.
  • The chromosomes begin to decondense and return to their stringy form.

 

 

 

5. Cytokinesis

  • Cytokinesis is the process of the separation of the nuclei into two daughter cells. This process is different for plant and animal cells. in plant cells a cell plate forms between the daughter cells. In animal cells cytokinesis is contractile, pinching the cell in two.