The Cell Cycle

Cell Division 8.2, P204

Objectives List the factors that lead to cell division Sequence the events of the cell cycle Explain how the length of the cell cycle varies

in different cell types

What limits cell size? Diffusion limits cell size DNA limits cell size Surface area-to-volume ratio

Cell division When one cell divides it produces 2 cells what are genetically identical to the original parent cell Cell division leads to: Growth of an organism Specialization of cells Repair of damaged tissues

Types of cells Prokaryotic Are cells that do not contain a nucleus. Genetic material is in the cytoplasm Example: bacteria Eukaryotic Are cells that contain genetic material inside the nucleus Example: plants, animals, protists, & Fungi

Cell Division in Prokaryotes Binary fission: the way prokaryotes reproduce. A parent splits in two, producing two genetically identical daughter cells.

Cell division in Eukaryotes Both the cytoplasm and nucleus divide during

eukaryotic cell division. Cell division results in two new cells with genetic material that is identical to the original cell. Mitosis may occur in the reproduction of unicellular organisms and in the addition of cells to a tissue or organ in a multi-cellular organism.

The Cell Cycle

The Cell Cycle The repeating pattern of events that make up the

life of a cell is called the cell cycle. Cell division is just one part of the cell cycle. The time between cell divisions is called interphase, which is divided into three phases:

 G-1 phase: Cells grow & carry out normal functions

(Cells may exit the cell cycle from the G-1 phase and enter a state called G-zero phase. Example: fully developed cells in the central nervous system.)  S phase: DNA copied  G-2 phase: cell prepares for cell division

By: Ms. Nina Abdelnaby I helped: Youssef Shaker I didn’t: Mostafa Galal