Biology B1.1 D - The effects of genetic variants

Question	Answer
What is a mutation?	A change in the sequence of bases in DNA.
What can cause mutations?	Some substances (including substances in cigarette smoke), by ionising radiation, but mostly by errors when DNA is copied.
What is point mutation?	When a nucleotide is substituted for another.
Why may point mutation not cause any effect?	Because several different triplets can code for the same amino acid.
What is insertion mutation?	When an extra amino acid is added, changing the way the bases are divided into triplets.
What is election mutation?	When an amino acid is removed, changing the way the bases are divided into triplets.
What happens when there is copying error when gametes are made?	If the gamete is fertilised, every cell of the developing organism will have the variant.
What are some effects of a mutation in offspring?	They could be harmful, either causing diseases, or causing the embryo to die. Or they could help the organism to survive better.
What happens if mutation happens in non-coding DNA?	Gene expression could be affected.
What is an example of a beneficial mutation?	Opposable thumbs.

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	Created by lily bevan almost 7 years ago