5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies or organs for transplantation

When evaluating, you just need to go over the positives and negatives and weigh up which is more (more positives or more negatives)

Positives

- Animals can produce medicines in their milk. Human genes can be transferred into animals to produce human antibodies to fight illnesses such as arthritis, multiple sclerosis and some types of cancer.

- Animals have organs suitable for transplant into humans (e.g. pigs). They could be developed by genetic engineering then cloned.

- Farmers do not have to wait for a 'good animal' like with normal breeding, all their animals could be beneficial with cloning

Negatives

- Cloned animals MAY not be as healthy as normal animals

- Lots of mistakes; embryos from cloned animals often do not develop well/efficiently/normally

- It is difficult, expensive and time consuming

- There may be long term risks that we are unaware of

5.19 describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an enucleated egg cell, illustrated by Dolly the sheep

Dolly is just used as an example as she was the first cloned mammal. The method is as follows...


- Remove the nucleus of an egg cell. This creates an enucleated egg cell (just a cell without a nucleus)

- Insert the nucleus of a diploid cell of the mammal you want to clone

- shock the new cell by electric shock to start division by mitosis. This creates an embryo

- Implant the embryo into the uterus of a surrogate mother (has to be the same species) to develop.

Now wait for the animal to be born

5.18 understand how micropropogation can be used to produce commercial quantities of identical plants (clones) with desirable characteristics

If loads of plants are required, you can take cuttings from the explants to produce even more plants. It is also very quick so the farmer will not need to rely on the correct conditions like during natural growth - the commercial company can ensure they ill have stock (of plants).

NOTE: the process of micropropogation is explained in point 5.17.

5.17 describe the process of micropropogation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

Micropropogation is a technique used to clone plants. Here's how it works...

- A plant with desired characteristics is selected to be cloned. Small pieces are cut from the tips of the stems and the side shoots of the plant (these cuttings are known as explants)

- The explants are sterilized to kill any microorganisms

- The explants are grown in vitro. All this means is that they're placed in a petri dish that contains a nutrient medium. This medium has all the stuff the plant needs to grow. It also contains growth hormones (auxins)

- The explant begins to grow and are taken out of the medium and planted in soil.


These plants develop into plants that are genetically identical to the original plant, meaning they will share the same characteristics.