Mutations

Question 1

What is cancer?

Answer 1

DNA mutation that causes uncontrolled cell division. Malignant tumour.

Question 2

How do cell mutations cause uncontrolled cell division?

Answer 2

They alter the primary structure of proteins which prevents them from controlling cell division.

Question 3

How does chemotherapy stop cell division?

Answer 3

It prevents DNA polymerase and DNA helicase. This prevents transcription of DNA so it cannot be replicated.

Question 4

What is a mutation?

Answer 4

Change in the arrangement of bases in a gene or in the structure of a chromosome.
Arise spontaneously during DNA replication.
Cause base deletion, substitution. May result in a silent mutation.
Evolutionary protective measure.
Can also arise by chromosome non disfunction during meiosis.

Question 5

What is a nonsense mutation?

Answer 5

When a mutation causes premature termination as a stop codon is coded for.

Question 6

What is a mis-sense mutation?

Answer 6

When a different amino acid is produced

Question 7

What is a silent mutation?

Answer 7

When the same amino acid is still produced.

Question 8

What is chromosome non disjunction?

Answer 8

When chromosomes fail to separate during meiosis.
Results in a gamete with either one missing or one extra chromosome

Question 9

What is a deletion mutation?

Answer 9

Base is deleted.
Leads to a frameshift

Question 10

What is an addition or duplication mutation?

Answer 10

Base is added or multiplied.
Leads to a frameshift

Question 11

What is an inversion mutation?

Answer 11

The genetic code is flipped.

Question 12

What is a translocation mutation?

Answer 12

A whole section of DNA is transferred to another section