1/17/10 Blog

This week in science, we learned about the cell cycle.

We learned that different cells go through the cycle different amounts of times. The cycle consists of:

1. Gap 1-in which the cell grows and makes proteins, interphase takes place
   
2. synthesis
3. Gap 2- in which the cell grows and the DNA replicates(copies)
4. Mitosis- in which each cell receives chromosome copies
   
5. Cytokinesis

Before a cell enters the synthesis stage, it checks if it is big enough and if the environment it is in is suitable. Between Gap 2 and Mitosis, the cell checks if the DNA is replicated, and during mitosis, the cell checks to make sure the chromosomes are alligned. Mitosis takes place in a very short amount of time. Cells spend 50% of their time in interphase, 27% of their time in prophase, 8% of their time in metaphase, 5% of their time in anapahse, and 2% of their time in telophase.

Many different things happen in mitosis, like: During anaphase, sister chromatids move apart; in Telophase, a new nuclear membrane forms around chromosomes and the cell's cytoplasm is divided; In, Prophase, the spindle is formed and the nuclear membrane and nucleolis begin to fade from view. Many things happen in Mitosis!

Also, by labeling pictures, we learned about identifying what stages of mitosis cells are in.

This is all very important to know because, cells are in and all around us, and it is important for us to know their life cycle.