Answer: Deletion of paternal chromosome 15q11-q13 (or maternal UPD15).
- A Trisomy of chromosome 15 arising from meiotic nondisjunction
- B Deletion of paternal chromosome 15q11-q13 (or maternal UPD15)
- C Deletion of the equivalent maternal region on chromosome 15
- D Presence of an extra X chromosome in a male karyotype
Correct answer: B. Deletion of paternal chromosome 15q11-q13 (or maternal UPD15)
Explanation: Prader-Willi: loss of paternal 15q11-q13 (imprinted region). If maternal copies of same region are lost, different disease (Angelman syndrome) results.
Punnett square for a monohybrid cross between two heterozygous (Tt) parents, showing the 3:1 phenotypic ratio predicted by Mendel's Law of Segregation.
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 →