Why are organisms different?
- Created by: JessicaGrey
- Created on: 09-04-16 15:07
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- Why are organisms different?
- Genes give offspring similar characteristics to their parents- passed on by gametes
- The nucleus of a cell contains chromosome. Chromosomes carry genes that control the characteristics of the body
- Differences in characteristics are caused by...
- Environmental factors eg accent, relgion etc
- Genetic factors eg height, eye colour, metabolism etc
- Both eg weight, hair colour
- Reproduction
- Sexual reproduction- egg and sperm cell fuse. Mixture of genetic info from both gametes leads to variabtion
- Asexual reproduction- one parent, no mixing of genes, no variation = clones
- Plants can be cloned by taking a cutting and sticking it in a rooting compound (hormone)
- This will encourage roots to grow
- Modern cloning techniques
- Tissue Culture (plants)
- Cells taken from parent plant. Put in nutrient agar. Small clone plants grow.
- Embryo Transplant (animals)
- Fertilize egg cell. The cells grow to become an embryo (ball of unspecialised cells) The embryo is split into multiple balls of cells. Then implanted into host mother.
- Adult Cell Cloning
- 1) Take skin cell from sheep A (take you want to clone)
- 2) Take egg cell from sheep B
- 3) Insert the nucleus of sheep A cell into empty sheep B cell.
- 4) Give cells an electric shock to stimulate growth.
- 5) Implant egg cell into sheep C (host mother)
- 4) Give cells an electric shock to stimulate growth.
- 3) Insert the nucleus of sheep A cell into empty sheep B cell.
- 2) Take egg cell from sheep B
- 1) Take skin cell from sheep A (take you want to clone)
- Tissue Culture (plants)
- Genetic engineering- transfer of genes
- Desirable genes can be "cut out" of chromosomes by enzymes and transferred to cells of other organisms
- Crops that have had their genes modified are called genetically modified crops (GM crops)
- GM crops have increased yields, useful for feeding a growing population.
- There are concerned about the effect of GM crops on wild flowers and insects and whether eating GM food may harm human health.
- Genes give offspring similar characteristics to their parents- passed on by gametes
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