Question

The most striking example of point mutation is found in a disease called
A. Thalassemia
B. night blindness
C. Down’s syndrome
D. Sickle-cell anaemia

Answer 1

Hint:
Let's discuss what point mutation seems to be first before learning the solution.
Point mutations are the kind of mutations that occur when a nitrogen base in a DNA strand is added, removed, or replaced with another, changing the codon and ultimately the protein. Example: In Sickle Cell Anemia, valine is used instead of glutamate's codon. The various kinds of point mutations include: One nucleotide gets swapped out for another in the substitution process.

Complete step by step answer:
A point mutation is an example of sickle-cell anaemia. It is a hereditary disorder that has been linked to black people and is caused by a molecular variation in the HbA gene on chromosome 11, which produces the β-chain of adult haemoglobin. The nucleotide triplet CTC is changed to CAC in this condition; because this change occurs at a specific location on the chromosome, it is referred to as a point mutation.
Sickle cell anaemia results from the early death of the cells, which can also impede blood flow and cause pain (sickle cell crisis). Sickle cell disease symptoms include infections, discomfort, and exhaustion. Medication, blood transfusions, and bone marrow transplants are occasionally used as treatments.
Therefore, Sickle-cell anaemia, a disease, is the most dramatic example of a point mutation.

Option ‘D’ is correct

Note:
Proteins are more likely to misfold or unfold when there are point mutations involving highly polar and charged amino acids. It has been suggested that both amino acid identity and its corresponding site-specificity impact a protein's stability when natural amino acids are substituted at locations with varying numbers of non-bonded contacts.