CELL DIVISION

■ Define Cell Division■ Explain the importance of Cell

Division.■ Identify the kinds of cell division.■ Describe the events in cell cycle.■ Examine the steps of Mitosis■ Compare mitosis in plant and in

animal cells.

STUDENTS WILL…

VOCABULARY

■ Cell Division■ Mitosis■ Chromosome■ Chromatids■ Centromere■ Interphase■ Cytokinesis

Cell Division

■ A process in which a parent cell divides into 2 daughter cells.

WHY?

• GROWTH• REPLACE WORN OUT

CELLS/DAMAGED CELLS

KINDS OF CELL DIVISION

■ MITOSIS & MEIOSIS (Eukaryotes)■■ Binary Fission (Prokaryotes)

http://www.youtube.com/watch?v=lpAa4TWjHQ4

The Cell Cycle

■ -The sequence of growth and division of a cell.

■ -95% of cell cycle in interphase■ -5% of cell cycle in mitosis

CELL CYCLE

STEPS IN CELL DIVISION:

INTERPHASE

■ -Preparation phase■ -Where cells spends

the majority of its time■ -“living phase of the

cell”■ -Where duplication of

DNA happens

3 stages of Interphase:

■ 1.Growth Stage 1 (G1) – cell grows and function properly.

■ 2.Synthesis Stage (S) – duplication of DNA

■ 3.Growth Stage 2 (G2) – cell resumes growth, preparation for Mitosis

MITOSIS

■ Stages:

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

- The process of cell division which results in the production of two daughter cells from a single parent cell.

Important to know:

■ Chromatids

-identical DNA strand❑ Centromere-

-a region of DNA at The middle ofChromosome wherethe sister chromatidsCome in contact.

Prophase■ Chromatids

are visible■ Nucleolus,

nuclear membrane disintegrates

■ Spindle fibers begin to form

PROPHASE

ANIMAL CELL PLANT CELL

Metaphase

■ Chromatids pair align at the center. (equatorial plate)

■ Centromere attached to spindle fiber.

METAPHASE

ANIMAL CELL PLANT CELL

Anaphase

■ Each chromatid pairs splits at the centromere and move at the opposite side.

■ Spindle fiber begins to shorten

ANAPHASE

Animal Cell Plant Cell

Telophase

■ Chromosomes moved into opposite poles.

■ Nuclear envelopes reforms.

■ Spindle fiber disappear.

■ Cytoplasm begin to separate.

TELOPHASE

Animal Cell Plant Cell

Cytokinesis

❑ Cytoplasm divides■ Two new daughter

cells are formed.■ New cells will enter

interphase and again cell division happens

Animal Mitosis -- ReviewInterphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

Plant Mitosis -- Review

Interphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

RESULTS OF MITOSIS:

1. Division of nucleus.

2. Production of 2 nuclei identical to each other.

3. Nucleus has the same number of chromosomes and type.

23 pairs = 46 chromosomes

What type of human cells does not undergo cell division?

■ Nerve Cells■ Brain Cells■ Heart Muscle Cells■ Liver Cells■ Kidney Cells