CBSE 2025 · Region 1 · Set 1 · Q1 · 1 mark
A man whose father was colour-blind marries a woman who had a colour-blind mother and normal father. What percentage of male children of this couple will be colour-blind ?
Official answer
From CBSE’s own marking scheme for this paper.
(C)
$\displaystyle 50$%
Principles of Inheritance and VariationSex DeterminationApplymcqmedium
Practice Principles of Inheritance and Variation →All Principles of Inheritance and Variation questions
More from Principles of Inheritance and Variation
- Using a Punnett square workout the distribution of an autosomal phenotypic feature in the first filial…2025 · asked 3×
- By using Punnett square depict the genotypes and phenotypes of test crosses (where green pod colour (G) is…2023 · asked 3×
- Assertion: In dihybrid crosses involving sex-linked genes in Drosophila generation of non-parental gene…2025 · asked 3×
- The following pedigree chart shows the inheritance of a genetic disorder up to three generations of a family.…2023 · asked 3×
- Write the types and locations of the genes causing thalassemia in humans. State the cause and symptoms of the…2026 · asked 3×
- A person with trisomy of 21^ st chromosome shows (i) Furrowed tongue (ii) Characteristic palm crease (iii)…2024 · asked 3×
- The chromosome number is fixed for all normal organisms leading to species specification whereas any…2023 · asked 3×
- A student performed some crosses in plants and represented the result in the form of bar graphs as shown…2026 · asked 3×
CBSE Class 12 Biology past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.