Human individuals are unique, yet modern science has the ability to create genetically identical copies of complex organisms. This item considers the advantages and disadvantages of using this scientific knowledge. Finding out about the techniques used to produce Dolly the first cloned animal provides the opportunity to illustrate the use of ICT in science, ethical issues about contemporary scientific developments and the role of the science community in validating changes in scientific knowledge.

Suggested activities and experiences to select from:

Research information on the techniques used to produce Dolly, the first cloned mammal.

Assessable learning outcomes:

Foundation tier only:

Interpret information on cloning techniques to show that:

• cloning is an example of asexual reproduction;
• cloning produces genetically identical copies (clones).

State that Dolly the sheep was the first mammal cloned from an adult.
State that identical twins are naturally occurring clones.

Both tiers:

Describe in outline the cloning technique used with embryo transplants in cows:

• sperm collected from selected bulls;
• selected cows artificially inseminated;
• embryos collected;
• embryos split, forming clones;
• embryo clones implanted into surrogate cows.

Recall that suitable organs for transplant could be produced by cloning animals.
Recognise that there are ethical dilemmas concerning human cloning.
Describe the advantages and disadvantages associated with the commercial use of cloned plants:

• advantage: can be sure of the characteristics of the plant since all plants will be genetically identical;
• advantage: it is possible to mass produce plants that may be difficult to grow from seed;
• disadvantage: if plants become susceptible to disease or to change in environmental conditions then all plants will be affected;
• disadvantage: lack of genetic variation

Higher tier only:

Describe in outline the cloning technique used to produce Dolly:

• nucleus removed from an egg cell;
• egg cell nucleus replaced with the nucleus from an udder cell;
• cell implanted into another sheep;
• cell grows into a clone of the sheep from which the udder cell came.

Discuss the benefits and risks of using cloning technology.
Discuss the possible implications of using genetically modified animals to supply replacement organs for humans.
Discuss the ethical dilemmas concerning human cloning.
Describe plant cloning by tissue culture:

• selection for characteristics;
• large number of small pieces of tissue;
• aseptic technique;
• use of suitable growth medium and conditions

Explain why cloning plants is easier than cloning animals:

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