Same chapter4 marksDifficulty: Hard
In a dihybrid cross between plants with round yellow seeds (RRYY) and wrinkled green seeds (rryy), give the F1 and the phenotypic ratio of the F2.
Genetics
4 marksDifficulty: Hard
Using a Punnett square, work out the offspring of a cross between two heterozygous tall pea plants, and give the phenotypic and genotypic ratios.
Original Khojo Papers practice question — not from a past board paper.
Answer
The offspring are 1 TT : 2 Tt : 1 tt, a genotypic ratio of 1 : 2 : 1 and a phenotypic ratio of 3 tall : 1 dwarf.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Each parent produces T and t gametes in equal numbers, and the square combines them in all four ways.
Related questions
From the same topic and chapter, at a similar level.
Same chapter4 marksDifficulty: Hard
A man with blood group AB marries a woman with blood group O. State the blood groups possible in their children and explain.
Genetics
Same chapter3 marksDifficulty: Medium
Explain sex determination in human beings.
Genetics
Same chapter2 marksDifficulty: Easy
State Mendel's law of segregation.
Genetics
Same chapter3 marksDifficulty: Medium
State Mendel's law of independent assortment and name the cross that demonstrates it.
Genetics
Same chapter2 marksDifficulty: Easy
Define the terms genotype and phenotype.
Genetics