Chapter 1.2 - Genetic Mutations

Question 0

True or false. When a DNA mutation occurs by mitosis the mutation is not passed on.

Answer 0

True

Question 1

When can genetic mutations occur

Answer 1

During DNA replication by either mitosis or meiosis.

Question 2

True or false. DNA mutations due to meiosis can be inherited.

Answer 2

True.

Question 3

What are the 3 types of DNA mutation?

Answer 3

Substitutions - involves one base pair replacing another so only one base has changed.

Insertions - occur when an extra nucleotide base is inserted into the genetic code.

Deletions- occur where one base is removed from the genetic code.

Question 4

What type of mutations are known as a frame shift?

Answer 4

Insertions an deletions

Question 5

What are silent mutations?

Answer 5

Substitutions can be silent mutations. This means although one base pair has been changed, the triplet code still codes for the same amino acid and there is no effect on the polypeptide produced. This is because most polypeptide has more than one code. But sometimes substitutions can change the amino acid.

Question 6

What is the effect of insertion on the overall polypeptide

Answer 6

Insertion moves every base along one so a new triplet code is formed which means the likeliness of new amino acids being formed is high and therefore the polypeptide will not be the same as it was meant to be without the mutation.

Question 7

What are neutral mutations?

Answer 7

Insertions and deletions are neutral mutations so long as the resultant differentiation gives the organism no particular advantage or disadvantage. Some mutations give the organism advantages and disadvantages which are known as positive and negative mutations

Question 8

Give an example of a positive mutation for a animal

Answer 8

Evolution and adaptations. Different beaks of birds in the Galápagos Islands To feed on nuts and seeds and fruit and nectar.