Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
We discussed yesterday that cells can’t continue to grow bigger and bigger. The surface area to volume ratio becomes too small and diffusion can’t happen fast enough to meet the demands of the cell. To solve this problem, a growing cell divides to form two daughter cells which are identical copies of the original cell. •Prior to cell division, the DNA is duplicated to give each daughter cell a complete copy of DNA. •During division, the cytoplasm and organelles are divided up between the 2 cells. This results in 2 cells with a smaller volume. The Cell Cycle G0- Rest Mitosis = Division 2 daughter cells G2-Growth 2 •The volume of the cell increases again. •DNA is checked for mistakes. •Mistakes are either repaired or the cell is destroyed—Apoptosis Important note: G1, S, and G2 together make what is called INTERPHASE which means “between divisions.” DNA Size DNA Size S- Synthesis DNA is copied so both daughter cells will have a complete set of DNA •Cells are doing their job! •Some cells remain in rest forever (nerve cells) others never rest (bone marrow, skin). •This cycle is controlled by proteins called Cyclins and CDK’s G1- Growth 1 •The volume increases as the cell make organelles and proteins. •DNA in the nucleus is uncoiled because it is being used to make proteins and organelles.