Types Of Mutations Substitution Insertion Deletion Frame shift
Substitution A substitution is a mutation that exchanges one base for another (i.e. , a change in a single “chemical letter” such as switching an A to G. For example: CTGGAG CTGGGG
Insertion Insertions are mutations in which extra base pairs are inserted into a new place in the DNA. CTGGAG CTGGCCTAG
Deletion Deletions are mutations in which a section of DNA is lost or deleted. CTGGAG CTAG
Frameshift In a frameshift mutation one or mare bases or inserted, deleted the equivalent of adding or removing letters in the sentence. But because our cells read our DNA in three letter words, adding or removing one letter changes each subsequent word. This type of mutation can make the DNA sequence meaningless . For example: Original= the fat cat ate the wee rat Frameshift= the fat caatet hew eerat.
Sample Question 1. THE CAT SAW THE FAT RAT 2. THE CAT SAW THE RAT The change in Statement 1 to form Statement 2 is most similar to what type ofmutation? Insertion Deletion Substitution Frameshift
Sample Question The correct answer is G. Because the sentence is missing the word fat which occurs in deletion as it is the removal of a section of DNA.
Sample Question 5′AGAUCGAGU3′ -> 5’ACAUCGAGU3′ The chain above represents three codons. Which of the following changes would be expected in the amino acid chain if the mutation shown above occurred? F. The amino acid sequence would be shorter than expected. G. The identity of one amino acid would change. H. The amino acid sequence would remain unchanged. J. The identities of more than one amino acid would change.
Sample Question The correct answer is G because according to the codon chart if G is switched by a C then one amino acid is affected because now instead of coding for Arginine it now codes for Threonine.