Division Cycle of Plant Cell and Totipotency

                                                         
                                                    Hey there!
                           
          I would like to share what I have learned on the fifth week in Cellular and Developmental Biology classes. On this week, we have learned about Cell Cycle and Totipotency.I have learned about cell cycle in highschool but never heard of totipotency before. I think it was an interesting new knowledge.

                Firstly, the cell cycle is an ordered set of events, resulting in cell growth and division into two daughter cells.It happens in both plants and animal cells. It consist of G1 phase, S phase, G2 phase , Mitosis and Cytokinesis.  Mitosis consists of Prophase, Metaphase, Anaphase and Telophase. There are  regulations of the cell cycle which means the passage of a cell through the cell cycle is controlled by proteins in the cytoplasm-Cyclins. This is quite new to me and I did not understand about it before but along the lecture, one by one was explained and I came to some sort of understanding.
 The cytoplasm- cylins are :                  Cyclin-dependent kinases(Cdks)
  •a G1 cyclins (D cyclins)                     •a G1 Cdk (CdkA)
•S-phase cyclins (cyclin A)                    •an S-phase Cdk (CdkB)
•mitotic cyclins (B cyclins)                    •an M-phase Cdk (CdkB)                                  
                                                                     
                                                                     
                          Any damage to DNA before the cell enters S phase inhibits the action of Cdk2 thus stopping the progression of the cell cycle until the damage can be repaired. If the damage is so severe that it cannot be repaired, the cell self-destructs by apoptosis while any damage to DNA after S phase (the G2 checkpoint), inhibits the action of Cdk1 thus preventing the cell from proceeding from G2 to mitosis. 

                

                    After we had finished discussing about cell cycle, we also had learned about totipotency. From my understanding on the topic, totipotency is the ability for a single cell to develop into a whole organism.This happens because it contains the entire genetic information in its nucleus.

If  a we culture a plant cell it can become  a callus which is made up of a group of unorganized loose parenchyma cells which proliferate from parent cells through de-differentiation before becoming an embryo through re-differentiation or it could also from a callus into an organ. A plant cell can also become an organ without being an embryo  or callus.

 Manipulation of the auxin to cytokinin ratio in the medium can lead to the development of shoots, roots or somatic embryos from which whole plants can subsequently

             I am particularly interested in this topic and I am actually excited when I hear that we will eventually do a plant culture in another semester. I think I  still not very clear some parts in cell cycle but I will find a video that will help me learn. The next topic that we will learn next week is pollination and development of plant embryo. I can't wait~