Presentation is loading. Please wait.

Presentation is loading. Please wait.

10-2 Cell division.

Similar presentations


Presentation on theme: "10-2 Cell division."— Presentation transcript:

1 10-2 Cell division

2 2 phases of cell division
Mitosis: division of the cell nucleus, including DNA replication. Cytokinesis: division of the cytoplasm and organelles cytokinesis Pair share: how is cytokinesis different from mitosis?

3 Chromosomes Genetic material (DNA) is usually in thin strands.
Before cell division, it thickens into chromosomes Each chromosome makes a copy of itself , and attaches to a centromere. Nucleolus disappears. Nuclear envelope breaks down. WB: how many copies of DNA are present before cell division?

4 Cell cycle A series of events that cells go through as they grow and divide. The cell grows, prepares to divide, then divides into 2 daughter cells. The cycle resumes with each daughter cell.

5 Events of the cell cycle
G1: cells grow S: DNA replicates G2: preparation for mitosis M: mitosis and cytokinesis P/S: how long is interphase compared to mitotic phase?

6 Prophase First and longest phase Chromosomes become visible
Centrioles separate to opposite sides of the nucleus, forming a spindle of microtubules

7 Metaphase Lasts only a few minutes
Chromosomes line up across the center of the cell, held by fibers of the spindle. WB: where are the chromosomes in this phase?

8 Anaphase Sister chromatids split apart
Each moves to a different pole of the spindle as the spindle fibers contract.

9 Telophase 4th and last phase of mitosis Chromosomes uncoil
Frog cell telophase 4th and last phase of mitosis Chromosomes uncoil Nuclear envelope re-forms around each cluster of chromosomes Spindle breaks apart Nucleolus is visible in each daughter nucleus P/S: how is telophase like the reverse of prophase?

10 Cytokinesis: division of the cytoplasm
In animal cells, the cell membrane pinches in. In plants, a cell plate forms midway between the divided nuclei. The cell plate becomes a membrane, Later, a cell wall forms in the cell plate. Animal cell Plant cell

11 Summary 4 5 Name the stages of the cell cycle: 3 6 2 7 1


Download ppt "10-2 Cell division."

Similar presentations


Ads by Google