Mutation

This and the following pages conform the content included in :
Science Education Key Learning Area, Biology Curriculum and Assessment Guide (Advaned Level), Jointly prepared by the Curriculum Development Council and the Hong Kong Examination Authority 2002

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Syllabus

3.1.6

Mutation

*	gene mutation : the effect of gene mutation on amino acid sequence (e.g. sickle-cell anaemia).
*	chromosome mutation : changes in chromosome structure and chromosome number (e.g. Down syndrome).
*	the types of mutation : spontaneous and induced mutations.
*	that mutations can be enhanced by ionising radiations and chemicals. [Refer to Section 6.]
*	significance of mutation.

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Suggested Readings :

(1)	Advanced-level Biology for Hong Kong, by Y.K. Ho, SNP Manhattan Press (H.K.) Ltd. Bk 1, p.
(2)	New Understanding BIOLOGY for Advanced Level, 4th ed., by Glenn and Susan Toole, Stanley Thornes, p.
(3)	A-level Biology, by Phillips and Chilton, Oxford University Press, p.
(4)	Biology : Principles and Processes, by Roberts, Reiss and Monger, Nelson International, p.
(5)	Advanced Biology principles and applications, ISE, by C.J.Clegg with D.G. MacKean, John Murray, p..

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Mutation is a change in genetic material and result in a hereditary trait.

There are two situations for mutations to occur.

(1) Spontaneous mutation,
Spontaneous mutatons occur spontaneously. It may be due to the error in transcription or translation. Also, it can be the result of responses against the contaminations of natural radiations or natural occurring chemicals.

(2) Induced mutation,
Induced mutations are the changes induced by artificial radiations or artificial arranged chemical contaminations.

Different genes are different in susceptibility of changes towards the same origin of induction. If it is not easy to make a gene change, the gene is said to be a stable gene.

If it is possible to make changes, the gene is said to be a mutable gene. Also, they can be considered as a unstable gene .

After receiving a certain dose of manipulation, a mutable gene can be changed and a new gene is formed. This new gene is called a mutant gene . The agent that causes change is called a mutagen.

(23.05.2007)