It is for my genetics class

Question

A researcher notices that at the same location in two copies of supposedly identical DNA, one DNA molecule has an A base, whereas the other has a C base. This researcher has just identified a:

Answer 1

This is a transcription error.

 

Transcription errors can be classified according to many factors, e.g., location, type, etc.  Therefore it may be relevant to your analysis to recognize that you have two clues:  the error occurs at the base (versus the end or another location), and the error is a transcription between A and C.

 

A point mutation is a kind of transcription error, where a single nucleotide is replaced by another.  However, you are not (yet) given complete information -- the statement does not preclude an additional insertion or deletion.  In fact, my first read would be that this is what the researcher noticed -- a single change.  Noticing one change often leads to further investigation.  So, if you do make the assumption that this is a point mutation, you should also state the assumption that there are no other errors in this codon.

 

You can read more here:

http://www.chemguide.co.uk/organicprops/aminoacids/dna6.html

http://www.ncbi.nlm.nih.gov/books/NBK21114/

 

 

Answer 2

Hi Nazom,

 

If single base pair substitution alters the protein sequence then it is a point mutation, if it does not then it is called: single nucleotide polymorphism or SNP.

 

Hope this is helpful as well. 

 

 

 

Answer 3

In general this is point mutation.