U8T2 – Mutations and Cancer

What does the term 'Degenerate' mean when referring to the genetic code?

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop What would be the order of amino acids in a polypeptide coded from this sequence?

TTCTTGTTATCATAA

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTATTATCATAA.

What type of mutation has occurred ?

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTATTATCATAA.

Will this mutation affect the primary structure of the polypeptide ?

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTGTTATAACATAA.

What type of mutation has occurred?

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTGTTATAACATAA.

What will be the effect on the mutated polypeptide?

What type of mutation causes a sequence of bases to be reversed?

What type of mutation causes a sequence of bases to be moved from one location to another?

What word describes when a mutation causes all the following triplet codes to be misread in a different frame?

Which type of mutation will not cause a frameshift?

Which of the following would have the most dramatic effect on the primary structure of the polypeptide produced?

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes.

The incidence can also be produced due to exposure to certain agents called mutagenic agents. These can be chemicals such as nitrous acid, which converts cytosine to uracil. Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene.

UV radiation is also a mutagenic agent. It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes. The incidence can also be produced due to exposure to certain agents called mutagenic agents.

These can be chemicals such as nitrous acid, which converts cytosine to uracil. Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene. UV radiation is also a mutagenic agent.

It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes. The incidence can also be produced due to exposure to certain agents called mutagenic agents.

These can be chemicals such as nitrous acid, which converts cytosine to uracil. Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene.

UV radiation is also a mutagenic agent. It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes. The incidence can also be produced due to exposure to certain agents called mutagenic agents. These can be chemicals such as nitrous acid, which converts cytosine to uracil.

Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene. UV radiation is also a mutagenic agent.

It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Cancer is often caused by a mutation causing a cell to divide uncontrollably and spread into other tissues. Name the gene that normally slows or reduces cell division:

Cancer is often caused by a mutation causing a cell to divide uncontrollably and spread into other tissues. Name the gene that normally increases cell division:

If a tumour suppressor gene mutates, then it can mean the protein it codes for is non-functional. What will happen to the rate of mitosis if this happens?

Methylation of DNA is when a methyl group ( CH3) is added onto CpG bases ( cytosine and guanine next to each other). This can stop DNA polymerase from binding.

What effect will increased methylation (Hypermethylation) have on transcription?

If hypermethylation happens to a tumour suppressor gene, what effect will this have on the rate of mitosis?

If hypomethylation ( reduced methylation) happens to a tumour suppressor gene what effect will this have on the rate of mitosis?

If hypermethylation happens to a proto-oncogene, what effect will this have on the rate of mitosis?

If hypomethylation (reduced methylation) happens to a proto-oncogenes gene, what effect will this have on the rate of mitosis ?

Long term exposure to Oestrogen can increase the risk of developing breast cancer. The exact mechanism is still not fully understood, but which of the following is definitely NOT a suggested mechanism ?

Which of the following would NOT increase your exposure to oestrogen?