Mutations are Changes to the Genetic Code Flashcards
Occasionally a gene may?
Mutate
What is a mutation?
A rare, random change in an organisms DNA that can be inherited
Who do mutations do?
Change the sequence of the DNA bases
What could this stop?
The production of a protein, or it might mean a different protein is produced instead
What can this lead to?
New characteristics increasing variation
Mutations can happen spontaneously -
When a chromosome doesn’t quite copy itself properly
How can the chance of mutation increase?
By exposing yourself to:
- ironising radiation e.g X-Rays
- chemicals called mutagens e.g chemicals in tobacco
Mutations are usually…
Harmful
What happens if a mutation occurs in reproductive cells?
The offspring might develop abnormally or die
What happens if a mutation occurs in body cells?
The mutant cells may start to multiply in an uncontrolled way and invade other parts of the body (which is cancer)
What is an example of a mutation having no effect at all?
If they occur in an unimportant part of the DNA - mutation is said to be neutral
Very occasionally, mutations are…
Beneficial and give an organisms a survival advantage, so it can live on in conditions where others die - natural selection at work
What is an example of a mutation being beneficial?
A mutation in a bacterium might make it resistant to antibiotics. If mutant gene is passed on, you might get a resistant ‘strain’ of bacteria which antibiotics can’t kill
