5.1MITOSIS

• Explain the importance of controlled mitosis.

• Explain the effects of uncontrolled mitosis in living things.

• Describe the application of knowledge on mitosis in cloning.

• Explain the advantages and disadvantage of cloning.

Learning Outcomes

• The genetic information carried by the chromosome - proper functioning of an organism.

• Each types of cell has its own timing of cell division- normal growth, development and maintenance.

• Regulate the entire process of cell division - each cell has a control system to ensure the cell division is complete and divide in a control manner.

• Certain gene control the cell cycle - Stimulate the formation of chromatin during the S phase.

THE IMPORTANCES OF CONTROLLED MITOSIS

• Cell divides through mitosis repeatedly without control and regulation can produced cancerous cells.

• The abnormal production of a mass of cells called a tumor.

• These cells compete with the normal cells to obtain nutrients and energy for growth.

• The tumor will invade and destroy neighbouring cells.

EFFECTS OF UNCONTROLLED MITOSIS

• Cancer can be caused by Explosure to ionising radiation

such as X-rays, UV rays and gamma rays.

Certain chemicals that are carcinogenic such as tar in tobacco and formaldehyde

Certain viruses

It’s All About CloningWhat Do You Know

About

CLONING?

Cloning – is the process of producing genetically identical organisms or clones through reproduction

TISSUE CULTURE• The growth of tissues or cells in a suitable and sterile

culture medium containing nutrients and growth hormones to produce new organisms that are identical to the parent.

• The new organisms produced are called clone.• Various part of plants can be cultured.• Animal cloning involve the replacement of the nucleus of

unfertilised egg cell with the nucleus from a somatic cell. The embryo is produced by mitosis which develops into a clone.

APPLICATION OF KNOWLEDGE ON MITOSIS IN CLONING

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Cut a piece of explants tissue and sterilised Cultured in sterile medium

Tissue divide by mitosis form callusand differentiate

Embryo develop into plantlets

ADVANTAGES AND DISADVANTAGE OF CLONING

ADVANTAGES DISADVANTAGES-Large number of clones can be produced in short time.- Crops are resistance to herbicide, pest and disease.- Do not need pollinating agents- Produce flowers and fruits in shorter period.- Cloned produce higher and better quality plants and animal.

- Decreases genetic variation.- The resistance of the clone to the pest and disease is same.- Prevents natural selection: undergo mutations.- Human therapeutic cloning has raised many ethical, legal, moral, and religious issues.

Activity1) 5/6 members in each group. 2) The presentative groups please come forward and take only one article.3) Each group needs to discuss and write down the advantages and disadvantage of cloning.