Cloning

Question 1

Describe the two ways plants can be cloned

Answer 1

From cuttings:
1) Gardeners can take cuttings from good parent plants, and then plant them to produce genetically identical copies (clones) of the parent plant. These plants can be produced quickly and cheaply.

From tissue culture:
1) This is where a few plant cells are put in a growth medium with hormones, and they grow into new plants – clones of the parent plant.
These plants can be made very quickly, in very little space, and be grown all year

Question 2

Describe how you can clone animals using embryo transplants

Answer 2

An example:
Sperm cells are taken from a prize bull and egg cells are taken from a prize cow.
The sperm are then used to artificially fertilise an egg cell. The embryo that develops is then split many times (to form clones) before any cells become specialised.

Cloned embryos can then be implanted into lots of other cows where they grow into baby calves, which will be genetically identical to each other.

Question 3

Describe the process of adult cell cloning

Answer 3

Adult cell cloning involves taking on fertilised egg cell and removing its genetic material (the nucleus)

A complete set of chromosomes from an adult body cell e.g. skin cell is inserted into the ‘empty’ egg cell.

The egg cell is then stimulated by an electric shock – this makes it divide like a normal embryo.

When the embryo is a ball of cells, it’s implanted into an adult female to grow into a genetically identical copy of the original adult body cell

Question 4

Name some issues surrounding cloning

Answer 4

The study of animal clones could lead to a greater understanding of development of the embryo and of ageing and age related disorders.

Cloning could also be used to help preserve endangered species.

Cloned animals might not be as healthy as normal ones because they age faster.

Some people worried that humans might be claimed in the future. If this was allowed any success may follow many unsuccessful attempts e.g. children born severely disabled

Question 5

Describe the process of genetic engineering

Answer 5

1) A useful gene is “cut” from one organism’s chromosome using enzymes.
2) Enzymes are then used to cut another organism’s chromosome and then to insert the useful gene
3) Scientists use this method to do all sorts of things – the human insulin gene can be inserted into bacteria to produce human insulin.

Question 6

Genes can be transferred into animals and plants. What useful characteristics could animals and plants develop with this method?

Answer 6

1) Genetically modified crops have had the jeans modified to make them resistant to viruses insects or herbicides that could kill them.
2) sheep have been genetically engineered to produce substances like drugs in the milk can be used to treat human diseases.
3) Cystic fibrosis is caused by faulty genes. Scientists are trying to treat disorders like this by inserting working genes into the sufferers. This is called gene therapy.

Question 7

What are the pros and cons of genetically modified crops

Answer 7

Pros:

1) Genetically modified crops can increase the yield of a crop, making more food.
2) People living without certain nutrients in their diets could use genetically modified crops that contain the nutrients they are missing. For example, they’re testing “golden rice” that contains beta-carotene – lack of this substance causes blindness.

Cons:

1) GM crops will affect the number of weeds and flowers and population of insects that live in and around the crops – reducing farmland biodiversity.
2) A big concern is that transplanted jeans make it out into the natural environment. For example, the herbicide resistance gene may be picked up by weeds, creating a new super weed variety