Cell Cycle & Cell Division

Cell Cycle

Stages of the Cell Cycle Interphase Mitosis Cytokinesis

Animated Cycle

INTERPHASE

Interphase Stage before cell division starts Each chromosome in the nucleus makes an exact copy of itself.

Interphase Animal Cell Plant Cell Photographs from:

MITOSIS

Mitosis Process during which the material from the cell nucleus divides. Results in the production of two identical daughter cells from a single parent cell. Used during growth or repair of cells.

Stages of Mitosis (PMAT) Prophase Metaphase Anaphase Telophase & Cytokinesis

Prophase Nucleus Prepares for Cell Division Genetic material shortens and thickens Chromosome copies held together at their centers in “X” formation by centromere

Prophase Animal Cell Plant Cell Photographs from:

Metaphase Two copies of each chromosome line up in the center of the cell. Spindle fibers attach to chromosomes at the centromere (where they are joined).

Metaphase Animal Cell Plant Cell Photographs from:

Anaphase Spindle fibers pull chromosome copies apart One complete set is pulled to one side and the other complete set is pulled to the other side of the cell.

Anaphase Animal Cell Plant Cell Photographs from:

Telophase & Cytokinesis Cytoplasm pinches in at the center of the cell, dividing the original cell in half. 2 nuclei form Daughter cells are identical to parent cell.

Telophase & Cytokinesis Each daughter cell ends up with the same number of identical chromosomes and about half the organelles and cytoplasm.

Telophase Animal Cell Plant Cell Photographs from:

Mitosis Animation

Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Cell Cycle 1. Interphase2a. Mitosis: Prophase Mitosis: Metaphase 2c. Mitosis: Anaphase 2d. Mitosis: Telophase 3. Cytokinesis 2b.

Cell Cycle 2a. Mitosis: Prophase Mitosis: Metaphase 2c. Mitosis: Anaphase 2d. Mitosis: Telophase 3. Cytokinesis 2b. 1. Interphase

Cell Cycle 2a. Mitosis: Prophase Mitosis: Metaphase 2c. Mitosis: Anaphase 2d. Mitosis: Telophase 3. Cytokinesis 2b. 1. Interphase

MEIOSIS

Meiosis Type of cell division that produces sex cells (egg or sperm), which have only half the chromosomes of the parent cell. One parent cell produces four daughter cells. DNA replicates once, but the nucleus divides twice.

Meiosis I First division of meiosis Each chromosome copies itself, X, before this stage.

First Division of Meiosis Prophase 1 & Metaphase 1 –Each chromosome in a cell has a homologous, or similar, pair. –Pairs line up two-by two in the center of the cell. Anaphase 1: Each pair of homologous chromosomes separates from the other as they move to opposite sides of the cell. Telophase 1: Cytoplasm splits and two new cells form. Each daughter cell contains only one homologous chromosome of the chromosome pair. (Half of the original genetic material of the original cell).

Prophase I

Prophase I

Metaphase I

Telophase I

Meiosis II Second Division of Meiosis

Prophase 2: DNA does not replicate. Metaphase 2: Chromosomes again line up in the center of the cell, but this time single-file instead of in pairs. Anaphase 2: X-shaped chromosomes split and the copies separate. One copy goes to one side of the cell and the other is pulled to the other side. Telophase 2: Cell division is complete with 4 new cells that have half the number of chromosomes that the original cell had. Four haploid (one set of chromosomes) daughter cells are formed.

Prophase II

Metaphase II

Telophase II

Meiosis

Meiosis Animation

Mitosis vs. Meiosis Mitosis –Growth or repair of cells –Cell divides once –Two (diploid) daughter cells –Genetic information is identical Meiosis –Produces sex cells –Cell divides twice –Four (haploid daughter) cells –Half the genetic information is present

Comparison Animations etics/sciber/animatin.htm