DNA - Mutations Flashcards Preview

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Flashcards in DNA - Mutations Deck (12)
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0
Q

What is a point mutation?

A

• it is when one base pair replaces another

1
Q

What is a mutation?

A
  • it is a change in the amount of, or arrangement of genetic material in a cell
  • they cause changes to the sequence of nucleotides in a DNA molecule
2
Q

What does a nonsense point mutation do?

A

It changes the bases to that a stop codon is introduced, the polypeptide is truncated

3
Q

What does a missence point mutation do?

A

It changes a base so that it codes for a different amino acid, primary structure is altered

4
Q

What does a silent point mutation do?

A

It changes a base but still codes for the same amino acid

5
Q

What is an insertion/deletion mutation?

A

It is when one or more nucleotide pairs are inserted or deleted from s length of DNA, these cause a frameshift

6
Q

What does a frameshift do?

A

It alters the reading frame of the gene downstream of the mutation, so after the mutation it will cause a different sequence of amino acids to be coded for

7
Q

Why can a mutation effect the way that a protein functions?

A
  • a mutation can change the amino acid that is coded for or truncate the polypeptide
  • this could change the R group on the amino acid
  • this could then affect/change the bonding in the secondary or tertiary structure
  • this could then change/alter the the 3D shape and so change the function of the protein
8
Q

What effect could an insertion/deletion have on the structure of a protein?

A
  • more of an effect than a point mutation as all the amino acids after the mutation will change
  • this means that bonding between R groups will change which could change the 3D shape of the protein as the tertiary and secondary structure will be different
9
Q

Explain how a mutation can have neutral effects

A
  • a mutation can have neutral effects if it changes a base in a triplet but the amino acid that the triplet codes for doesn’t change
  • if the mutated triplet changes the amino acid but has no effect on the function of the protein
  • if the mutation occurs in non-coding parts of the DNA
10
Q

Explain how a mutation could have a beneficial effect

A

• could have an advantageous effect on an organism e.g. Increase its chances of survival

11
Q

Explain how a mutation could have harmful effects

A

• could have a disadvantageous effect on an organism e.g. decrease its chances of survival