Question

A point mutation changes the DNA sequence CGA to CGT, but the same protein is still produced. Which point mutation occurred? nonsense missense silent frameshift

Answer 1

The correct answer is silent mutation . In this type of mutation there is no change in  the phenotype of the individual which means there occurs a mutation where two different amino acid codes for the same protein .There are sequences present in the body where a point mutation occurs but the protein formed is still the same .If you will see the genotype you can easily observe that the amino acid sequence is different but the protein formed is same. Example AAA codes for lysine and the amino acid lysine is formed by AAG .

Answer 2

Silent mutation is occurred when the DNA sequence changes from CGA to CGT but the protein is remained same.

Explanation:

A gene mutation is defined as a change in the sequence of nucleotides in DNA. During protein synthesis, DNA is transcribed into RNA and then converted to proteins. It also led to the genetic variation.

However, a change in DNA occurs but in silent mutation it doesn’t change the protein that is to be produces. It is because multiple codons can 'encode' for same 'amino acid'.

Amino acid is formed by 'three nucleotide sets' called codons which includes CGC, CGT, CGA and CGG. If DNA sequence 'CGC' is changed to 'CGA', the composition of arginine remains the same.