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Medium trendapprox. 5 marksSections B/C — Mendel's experiments and monohybrid / dihybrid Punnett squares.
CBSE 2027 — dates, rules and official papers →Ask the tutor1Always label parents, gametes and generations (P, F₁, F₂) on the cross diagram.
Notesformulae · proofs · mind-map — one view
Learn the 6 conceptsteach yourself first, then practise each
Accumulation of Variation during Reproduction1–5 marks
Explain why imperfect DNA copying brings small variations, why sexual reproduction adds more, and that they pass to the next generation.
Mendel's monohybrid cross (3:1 phenotypic ratio in F₂)3–5 marks
Set up parents and gametes, then a 2×2 Punnett square.
Dominant vs recessive traits1–2 marks
Identify which trait expresses in the F₁ generation.
How Traits Get Expressed1–5 marks
Link gene → protein (enzyme) → trait, and explain why both parents contribute equally through paired chromosomes.
Sex determination in humans (XX vs XY)2–3 marks Visual
Show that the father determines the sex of the child.
Genotype vs phenotype1–2 marks
Distinguish the genetic makeup from the observable trait.
When you’re ready — practise or test the whole topic