- The cell nucleus contains chromosomes.
- These chromosomes are made up of genes, the male and female sex cells, gametes, contain the genes so the genetic information is passed on to the offspring.
- Genes control the development of the characteristics in the offspring.
- Chromosomes are made up of genes.
Types of Reproduction
- Sexual reproduction involves the fusion of sex cells (gametes.) There is a mixing of genetic information of the offspring show variation.
- Asexual reproduction doesn't involve the fusion of sex cells, all the genetic information comes from one parent. All of the offspring are identical to the parent.
- These identical indiviuals are known as clones.
Clones are identical to the parent. Cloning is used to produce new individuals that you want.
- In plants the process is cheap and effective. Plants can be cloned by taking cuttings of one plant and growing them seperately, or taking groups of cells and growing them under special conditions (tissue culture.)
- With animals it is much more difficult to clone. Embryo transplants are used to clone animals. In this process, embryos are split into smaller groups of cells then each group is allowed to develop a small host family.
New Ways of Cloning Animals
- Fusion cell and adult cell clong are also used to clone animals.
- In adult cell cloning, the nucleus of the animal you want is placed in an empty egg cell. This cell is then developed in a different animal.
A adult udder cell is taken from sheep A, the nucleus (containing all Sheep As DNA) is then removed from the udder cell.. A mature egg is taken from sheep B and the egg is removed, so all thats left is an empty egg cell. A mild electric shock fuses together the nulceus from Sheep A and the empty egg from Sheep B. The cloned embryo is then placed in the uterus of Sheep C. If all goes well the lamb born will be Sheep As clone.
Genetic engineering involves changing the genetic make up of an organism.
Genes are 'cut out' of the chromosomes of an organism using an enzyme. The genes are then placed in the chromosome of another organism.
The genes may be placed in an organism of the same species so that it has 'disired ' characteristics or in a different species. For example, the gene to produce insulin in humans can be placed in bacteria so that they produce insulin.
Many people agrue about whether or not genetic engineering is right. Will it create new organisms that we know nothing about? Is it going aganist nature?