Zaymiey

🔬 Biology  ·  Principles of Inheritance and Variation  ·  NEET

Epistasis occurs when:

Answer: One gene masks or modifies the expression of another gene.

  • A Two alleles of the exact same gene happen to interact
  • B One gene masks or modifies the expression of another gene
  • C All genes in the genome act largely independently of each other
  • D Genes located on the same chromosome generally do not interact

Correct answer: B. One gene masks or modifies the expression of another gene

Explanation: Epistasis: one gene (epistatic) suppresses or modifies the phenotype of another gene (hypostatic). Causes modified ratios (e.g., 9:3:4, 9:7, 12:3:1 instead of 9:3:3:1).

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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