Zaymiey

🔬 Biology  ·  Principles of Inheritance and Variation  ·  NEET

Epigenetics refers to:

Answer: Heritable changes in gene expression without DNA sequence change (e.g., methylation, acetylation).

  • A Permanent, irreversible changes occurring within the underlying DNA nucleotide sequence itself
  • B Heritable changes in gene expression without DNA sequence change (e.g., methylation, acetylation)
  • C Random point mutations that arise spontaneously during ordinary DNA replication
  • D Environmental effects that mainly influence seedling growth rate in young plants

Correct answer: B. Heritable changes in gene expression without DNA sequence change (e.g., methylation, acetylation)

Explanation: Epigenetics: heritable changes in gene expression not involving DNA sequence changes. Includes DNA methylation, histone modification.

Monohybrid Cross: Tt x TtParent 1 (Tt)Parent 2 (Tt)gametes: T, t (from each parent)TtTtTTTtTtttRatio 1 TT : 2 Tt : 1 tt (3 tall : 1 short if T = tall is dominant)

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.

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