Cloning

Question 1

Who was the first mammal cloned from an adult?

Answer 1

Dolly the sheep

Question 2

What are identical twins?

Answer 2

Naturally occurring clones

Question 3

How can plants be clones?

Answer 3

If they are grown from cuttings or tissue culture

Question 4

Describe how spider plants, potatoes and strawberries reproduce asexually

Answer 4

• Potato plants produce tubers. The tubers produce several buss, from which new plants grow
• Strawberry plants produce runners, from which new plants root and grow
• Spider plants produce runners from which new individual plants grow

Question 5

Describe how to take a cutting

Answer 5

When a gardener has a plant all the desired characteristics, he/she may choose to produce lots of them by taking stem, leaf or root cuttings. The cuttings are grown in a damp atmosphere.

Question 6

How was dolly the sheep produced?

Answer 6

By the process of nuclear transfer and that nuclear transfer involves placing the nucleus of a body cell into an egg cell

Question 7

Describe some possible uses of cloning

Answer 7

• mass producing animals with desirable characteristics
• producing animals that have been genetically engineered to provide human products
• producing human embryos to supply stem cells for therapy

Question 8

Understand the ethical dilemmas concerning human cloning

Answer 8

• the cloning process is very unreliable - the vast majority of cloned embryos do not survive
• cloned animals seem to have a limited life span and die early
• religious views say that human cloning is wrong

Question 9

Describe the advantages and disadvantages associated with the commercial use of of cloned plants

Answer 9

Advantages - can be sure of the characteristics of the plant since all plants will be genetically identical, it is possible to mass produce plants that may be difficult to grow from seed

Disadvantages- if plants become susceptible to disease or to change in environmental conditions then all plants will be affected, lack of genetic variation

Question 10

Describe plant cloning by tissue culture

Answer 10

• selection for characteristics
• aseptic technique
• use of suitable growth medium and conditions

Question 11

Explain why cloning plants is easier than cloning animals

Answer 11

Many plant cells retain ability to differentiate unlike animal cells which usually lose this ability at an early stage

Question 12

Describe the cloning technique used to produce dolly

Answer 12

• nucleus removed from an egg cell
• egg cell nucleus replaced with the nucleus from an udder cell
• egg cell given an electric shock to make it divide
• embryo grows into a clone of the sheep from which the udder cell came

Question 13

Describe the benefits and risks of using cloning technology

Answer 13

Advantages- genetically identical cloned animals will all have the same characteristics, it is possible for the farmer to choose the sex and timing of birth
Disadvantages- cloning reduces genetic variation in the herd, there is the potential for accumulating inherited diseases

Question 14

Explain the possible implications of using genetically modified animals to supply replacement organs for humans

Answer 14

Animal donors could solve the problem of waiting lists for human transplants. But there are concerns that infections might be passed from animals to humans, and there are ethical issues concerning animal welfare and rights.

Question 15

What is cloning?

Answer 15

• An example of asexual reproduction

- produces genetically identical copies