- A Large-scale deletion spanning the entire beta-globin gene cluster
- B Single base mutation in haemoglobin gene (point mutation)
- C Retroviral insertion disrupting globin gene expression
- D Complete loss of chromosome 11 in red cell precursors
Correct answer: B. Single base mutation in haemoglobin gene (point mutation)
Explanation: Sickle cell anaemia: single point mutation (GAG→GTG in DNA; glutamic acid→valine in protein) causes abnormal haemoglobin.
Concept context
Mendel's laws, inheritance patterns, DNA structure, and molecular biology. Core of NEET biology.
Read the full Principles of Inheritance and Variation notes →