70 likes | 124 Views
Genetic Mutations. Mu y tat og ns?. Insertion. A mutation in which extra base pairs are inserted into a new place in the DNA. CTGGAG. CTGG TGGA AG. Deletion. A mutation in which a section of DNA (or at least one base) is lost. CTGGAG. CTAG.
E N D
Genetic Mutations Muytatogns?
Insertion • A mutation in which extra base pairs are inserted into a new place in the DNA. CTGGAG CTGGTGGAAG
Deletion • A mutation in which a section of DNA (or at least one base) is lost. CTGGAG CTAG
Possible Results of Insertions or Deletions? “Frameshifts” • Since DNA mRNA and mRNA is read in codons (triplets), insertions and deletions can create amino acid sequences that are meaningless. • Consider the message: The fat cat ate the hat hefatcatatet heh at
Substitution • A mutation that exchanges one base for another. • Possible Results: • Change in codon change in amino acid. • Change in codon no change in amino acid. “silent mutation” • Change in codon to become a stop codon. “nonsense mutation” CTGGAG CTGGGG
Chromosomal Alterations • Can also lead to changes in DNA sequence new traits • Breakage of a chromosome may lead to four types of changes
The boy cut his lip and ate the hot dog Your tasks: • Copy the sequence and place a large box around it • Using the original sequence, insert two bases anywhere. Write the resulting message as it would be read. 3. Using the original sequence, delete one base anywhere. Write the resulting message as it would be read. 3. Using the original sequence, substitute one base to another. Write the resulting message as it would be read. Challenge: Write a DNA sequence and create a substitution that would result in a silent mutation.