Last Unit: Reproduction

Cell Division Cells divide in order to produce new cells Division allows all multicellular organisms to grow, maintain and repair themselves, and reproduce.

What we Remember About the Cell Cells come in a variety of shapes and sizes. There are some structures that are common to all cells. There are also some differences.

The Cell Cycle Is a process by which the parent cell grows, duplicates itself, and divides to produce new daughter cells, usually two.

There are three major phases in the cell cycle: 1. Interphase 2. Mitosis 3. Cytokinesis

1. Interphase - The longest phase of the cell cycle - The cell performs normal cell functions example: growing - Chromosome duplication in the nucleus

2. Mitosis - The nucleus divides - The nuclei produced are identical to each other and to the parent nucleus

Mitosis has four stages: 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase

Prophase

Metaphase

Anaphase

Telophase

3. Cytokinesis Differs between animal and plant cells: Animal Cells -The cell membrane pinches in to divide the nuclei, cytoplasm, and organelles to form two daughter cells - A cell wall forms between the two nuclei, dividing the cytoplasm and forming two daughter cells

Most cells are produced by mitosis In sexually reproducing species, body cells contain two sets of chromosomes, one set from the male parent and the second from the female Cells that have a double set of chromosomes are called diploid cells. Cells that contain only a single set of chromosomes are called haploid cells. (we will discuss haploid cells later on in the unit)

Mitosis

Cell Cycle and Cancer