Question

Gene has a base sequence that starts with: TAG CAT GGC AT.

A) The gene has a point mutation and is changed to the sequence below : TAG CTT GGC AT. What kind of mutation is this?

B) What is the new mRNA strand formed by this gene?

C) What are the new amino acids formed from this gene?

D) Describe how the mutation has affected the protein coded by this gene.

Answer 1

A. Substitution mutation

B. AUC GAA CCG UA

C. Isoleucine- Glutamic acid- Proline

D. It will lead to formation of a different protein

Step-by-step explanation:

According to this question, the gene has a base sequence that starts with: TAG CAT GGC AT but undergoes a kind of point mutation to become; TAG CTT GGC AT.

A. From the observation of the two base sequences, base A is substituted for base T in the second Codon i.e. CAT to CTT. This is an example of SUBSTITUTION MUTATION because it involves the replacement of a base nucleotide by another.

B. Following transcription, which is the synthesis of mRNA from a DNA template, the mRNA sequence from the mutated sequence is as follows: AUC GAA CCG UA

C. Following translation using the genetic code, the amino acid sequence that will result from the mutated sequence is as follows: Isoleucine- Glutamic acid- Proline

D. Due to the change in nucleotide base of a codon, a change in the amino acid sequence has occured. Hence, this will lead to the formation of a different protein.