Key Facts

• Most of your features are effected by your environment and your genes.

• Genes are found in the nuclei of cells and are the instructions for making proteins.

• Your chromosomes, and genes are in pairs.

• Genes have different versions - that are called alleles.

• Men and women have different sex chromosomes.

• We all have some features in common, we may look like our parents, brothers, sisters etc...
• Doctors can test embryos, fetuses and adults for certain alleles by genetic tests.

• Gene therapy could be used to treat some genetic disorders.

• Some organisms use asexual reproduction and have offspring that are clones.

• Animal clones are produced naturally and artificially.

• Cells in multicellular organisms become specialized very early in the organisms development.

• Stem cells can be used to treat certain genetic disorders.

DNA Cloning the Future

• Many living organisms only need one parent to reproduce~ asexual reproduction.

• Single-celled organisms like bacteria use asexual reproduction.

• The bacteria inherit the genes from only one parent, so the genes are identical to their parents are each other.

• We call genetically identical organisms clones.

• The only difference between them will be caused by their environment.

• Most animals use sexual reproduction.

• The offspring have two parents so they are not clones.

• Clones, however, are sometimes produced we call them identical twins.

• Identical twins have exactly the same genes, but they came from both parents. So they are clones of each other but not clones of their parents.

• Scientists have already cloned animals, this is much more difficult.

• Dolly the sheep was the first ever cloned sheep to be born.

How Dolly was cloned...

• The nucleus was taken from an unfertilized sheep egg cell. The nucleus is then taken out of a body cell from a different sheep, this body cell nucleus was put into the empty egg cell. The cell grows to produce a new animal, its genes will be the same as those animal that donated the body cell nucleus. So it is a clone of that animal.

• It took 277 attempts before Professor Wilmut's team managed to clone Dolly.

• Sadly Dolly died in 2003 aged 6. Dolly's illness may not have been to do with her being cloned, she may have died at an early age anyway, but one case is not enough evidence to decide.

• More research is needed to be done before cloned mammals will grow into healthy adults.