Normal Life of cell

Nerve Cells stop

at this point

46

92

Nuclear Division

Cell Division is controlled by the cells Surface to Volume Ratio

New healthy cell

Old tired cell

Mitosis Videos

During Cell Division the Genetic Material goes through three name changes

1. Chromatin – During Interphase, it is difficult to see because it is very thin and wispy

2. Chromosomes – Condensed, easier to see with a microscope. Looks like dark short threads.

Can be found in single or doubled form

3. Chromatids – Double Chromosomes, Look like little X’s under a microscope.

Two chromatids make up one chromosome

Chromatids

Doubled Chromosome

Chromatin

Chromosomes

Chromatids

I

P

M

A

T

Interphase

Nucleus

Genetic Material in

form of Chromatin

Cell Wall

Nucleolus

Prophase

Chromatids

Centrioles

Spindle Fibers

Nuclear Membrane

Centromere

e

Plant Cell Prophase

Replicated Chromosomes

convert to Chromatids

Metaphase

Chromatids

Centrioles

Animal Cell Metaphase

Chromatids

Centrioles & Asters

Spindle Fibers

Cell Membrane

Plant Cell Metaphase

Cell Wall &

Cell Membrane

NO Centrioles in Plants

Chromatids

Anaphase

Chromosomes

Centrioles

Anaphase in plant cell

Chromosomes moving toward poles

Telophase

Nucleolus

New Nucleus Forming

Membrane pinching in

Chromosomes turn back to Chromatin

Telophase

Division Plate

or

Cell Plate

Chromosomes

Cytokinesis

Cytokinesis

Video

Cytokinesis in Animal Cells

Cytokinesis in Animal Cells

Cell Furrow

Types of Cytokinesis

Binary Fission - Equal Division

Budding - Unslightly unequal

Sporulation – Very unequal

Note: The nucleus always divide equally during Mitosis

CancerNeoplasm - Abnormal cell growth, unregulated mitosis.

1. Benign - Not Cancerous, has not spread to other tissue.

2. Malignant – Is Cancerous, has spread to other tissues.

Cancer Cells:

1. Form Tumors – Undifferentiated cells that pile up.

2. Undergo Metastasis – Spread to other tissues

3. Produce Angiogenesis – Form new blood vessels

Cause of CancerOncogenes – Cancer causing genes formed by genetic mutation.

The mutation is undetected by the cells regulatory mechanism so apoptosis doesn’t occur.

There are about 100 know forms of Oncogenes

Oncogene formation can be caused by problems in gene replication during mitosis. ( Family History)

Environmental Factors can produce Oncogenes.

I.e.. UV radiation, smoking, asbestos

Summary

Quiz