Cell Division

Cell Division

1. Cell Division

   • Key points: In body cells, chromosomes are found in pairs. - The cell cycle is a series of stages where the cells divide. - Mitosis : During the cell cycle, genetic material is doubled before dividing to form two identical nuclei.
   • Mitosis is one stage in the cell cycle where two identical cells are produced from the original cell.
     • Mitosis

2. Growth and differentiation

   • Key points: - In plant cells, mitosis takes place throughout life in meristems found in the shoot and root tips. - Many types of plants cell retain the ability to differentiate throughout life. - Most types of animal cells differentiate at the early stages of development.
   • Differentiate - The process where cells become specialised for a specific function. i.e. muscle cell, skin cell etc...
   • Organisms start as one cell that then divides and multiplies by mitosis.
   • Cloning Plants vs Animals
     • It is easy to clone a plant as its cells can become unspecialised, divide by mitosis and then differentiate.
     • Animal cells are harder to clone as once their cells differentiate they can not become unspecialised again.

3. Stem Cells

   • Key points: - Embryonic stem cells (from embryos) and adult stem cells (from adult bone marrow) can be cloned and differentiate. - Stem cells may be able to help treat conditions such a paralysis and diabetes.
   • Benefits of stem cell research
     • Rare plants can be saved from extinction. - Large populations of genetically identical plants can be used for research. - Increases horticulture profits. - Genetically modified plants resistant to diseases.
     • Treat diseases, restore lost vision, produce cells that create insulin for diabetes patients.
   • Problems with stem cell research
     • Ethical objections - embryo rights, interference with nature, expensive and money wasted, process is slow, might cause cancer, adult stem cells can carry viruses.

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