5.1 The Cell Cycle

KEY CONCEPT A cell’s life consists of a repeating pattern of events called the cell cycle.

5.1 The Cell Cycle

Cell Cycle Events include:

• Growth • Carrying out is job• DNA and organelle duplication• Division

5.1 The Cell Cycle

The Cell Cycle is divided into two main stages:

Interphase and Cell Division

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5.1 The Cell Cycle

INTERPHASE

Purpose: Grow, Carry out Job, Prepare for Cell Division

G1 - Cell growth, Do job

Duplicate organelles

S - DNA synthesis (copies DNA)

G2 - Additional growth,

Duplicate organelles

Normal functions

5.1 The Cell Cycle

2 Parts of Cell Division “M” Stage:

1. Mitosis

2. Cytokinesis

5.1 The Cell Cycle

MITOSIS “Nuclear Divison”

Purpose:

Divides nucleus into 2 genetically identical nuclei

4 Stages of Mitosis:• Prophase• Metaphase• Anaphase• Telophase

5.1 The Cell Cycle

CYTOKINESISPURPOSE:

Divide the cytoplasm to form two separate cells

Animal Cell Plant Cell

5.1 The Cell Cycle

The Final Product of the Cell Cycle……

• 2 Daughter Cells that are genetically identical to the parent cell – same # of chromosomes with same DNA information

  

Start of Interphase End of Interphase/ End of Mitosis

Beginning of Mitosis End of Cytokinesis

5.1 The Cell Cycle

Reasons Cells Divide

• Growth• Replacement• Repair• Maintain size limit (surface area to volume ratio)

5.1 The Cell Cycle

Cell size is limited.

• Volume increases faster than surface area.

5.1 The Cell Cycle

Cells divide at different rates.

• The rate of cell division varies with the need for those types of cells.

• Some cells are unlikely to divide (G0) Ex. Neurons (nerves).