Answer: Parent-of-origin-specific gene expression (some genes expressed only from maternal or paternal allele).
- A The random chemical marking of DNA bases for methylation occurring during cell replication according to conventional understanding
- B Parent-of-origin-specific gene expression (some genes expressed only from maternal or paternal allele)
- C The random inactivation of one X chromosome occurring within female somatic cells in routine practice
- D The silencing of transposable genomic elements carried out by small interfering RNA molecules overall
Correct answer: B. Parent-of-origin-specific gene expression (some genes expressed only from maternal or paternal allele)
Explanation: Genomic imprinting: epigenetic silencing of one allele based on parental origin. E.g., IGF2 expressed from paternal allele only; H19 from maternal.
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 →