Genetic Manipulation

Form of artificial asexual reproduction

• Cut off a small piece of stem and dip the cut end in rooting powder
• Place it in prepared compost or soil and water it
• Cover the whole thing with a plastic bag to keep in all the moisture

Why use rooting powder?

By dipping the cut end in rooting powder, the chances of success are greatly increased because the hormone stimulates the growth of new rootsand helps the cutting grow into a new plant

- Helps commercial gardeners to produce huge numbers of successful cuttings to sell to the public

• Take a small tissue sample from the parent plant
• Grow the tissue in agar with a combination of nutrients and plant hormones
• This produces a big mass of identical plant cells called a callus
• Then, using a different mixture of hormones and conditions, stimulateeach of the cells to from a tiny new plant
• Grow the tiny plants to much bigger plants

A clone is an individual that has been reproduced asexually and isgenetically identical to the parent.

• Pick a top quality cow and bull
• Give the cow oestrogen to stimulate the release of eggs
• Fertilise these eggs using sperm from the bull to form a zygote
• Grow each zygote into a 16 cell embyro
• Divide each embyro into several individual cells and grow each cell into an identical embyro in the lab
• Implant each embryo into surrogate mothers who have been given FSHto stop the release of eggs
• Identical cloned calves are born.

Advantages:

• Can produce many identical animals quickly
• Can transport high quality frozen embryos all around the world to places where cattle with a high milk yield or lots of meat are needed for breeding
• Allows the production of more calves from the best cows

Disadvantages

• Expensive
• Requires someone who is trained in this field
• Only wealthy farmers/countries can afford the technology
• Some say it is morally wrong to produce identical animals
• If one has a disease, they'll all have it
• Reduces variety, therefore the population is less able to survive anychanges in the environment that might happen.

• The nucleus is removed from an unfertilised egg cell
• At the same time, the nucleus is taken from an adult body cell, e.g skin cell of another animal from the same species
• The nucleus from the adult cell is inserted into the empty egg cell
• The new egg cell is given a small electric shock which stimulates it to start dividing to form embryo cells
• When the embryo has developed into a ball of cells, it is inserted into asurrogate where it continues to grow.

Advantages:

• Animals that have been genetically engineered to produce useful proteins in their mlik can be cloned
• Used to help save animals from extinction, or bring back species of animals that have already died out
• Could help infertile couples

Disadvantages:

• Reduces variety, therefore the poplulation is less able to survive anychanges in the environment that might happen
• If the parent has an unknown disease the cloned animal will also have the disease
• Morally wrong
• Most clones from this method do not survive

Genetic engineering involves changing the genetic material of an organism by:

• You take a gene from one organism and transfer it to the genetic material of a completely different organism. Enzymes are used to isolateand cut out the required gene
• The gene is then inserted into a carrying vector using more enzymes. The vector is usually a bacterial plasmid or a virus
• The vector is then used to insert the gene into the required cells, which may be bacteria, animal, fungi or plants.

If genetically engineered bacteria are cultured on a large scale, they can make huge quantities of protein from other organisms. We now use them to make a number of drugs and hormones used as medicines.

• Can be made to be resistant to attack by insects because they have been modified to make their own pesticide - therefore more of the crops survive to provide food for people
• Some GM plants are more resistant than usual to herbicides meaning farmers can spray and kill weeds more effectively without damaging the crops - also increases the crop yield

Increasing crop yields is important for providing food security for the world:

- Genetic engineering has resulted in many cereal plants with much shorter stems than usual --> much less likely to be damaged by wind or storms - increases yield

- Some rice plants produce crops that can withstand being covered in water for up to 3 weeks during flooding and still produce a high yielding crop of rice - saves people from starvation

Advantages

• Improved growth rates of plants and animals
• Increased food value of crops, as GM crops usually have much bigger tields than ordinary crops
• Crops can be designed to grow well in dry, hot or cold parts of the world
• Crops can be engineered to produce plants that make their own pesticides or resistant to herbicides
• Pure human insulin is mass produced using genetically engineered bacteria

Disadvantages

• Often made infertile, therefore farmers have to buy new seeds each year
• People might want to manipulate the genes of future children - designer babies
• Could affect the population of wild flowers and insects