✓ Board-verified
Biology · 2024 · 3 marks
CBSE 2024 · Region 4 · Set 1 · Q23
(a) A man with blood group 'A' marries a woman with blood group 'AB'. The first child born to them has blood group 'B'. Work out a cross to find the…
(a)
A man with blood group 'A' marries a woman with blood group 'AB'. The first child born to them has blood group 'B'. Work out a cross to find the genotype of the father. Give the possible blood groups and their genotypes of the children that could be born to this couple. (Use a Punnet square).
(b)
State the basis of 'ABO' blood grouping in humans.
Marking-scheme solution
(a)
Father genotype - $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{i}$
Parents- $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{i}$ X $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}}$
Possible genotype- $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{A}}$ , $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{i}$, $\displaystyle \mathrm{I}^{\mathrm{B}} \mathrm{i}$, $\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}}$,
Possible blood group- A, AB, B
(b)
It is controlled by gene ‘I’ having $\displaystyle 3$ alleles ($\displaystyle \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} \mathrm{i}$) , The blood group is determined by the type of sugar polymer present on the plasma membrane of the RBC.
All Principles of Inheritance and Variation questions2024 question paperNCERT solutions: Principles of Inheritance and VariationPractice Principles of Inheritance and Variation →
More from Principles of Inheritance and Variation
- In which of the given chromosomal disorders does the individual have tall stature with feminised character?2024
- In the following figure, two ways of pairing of two homologous pairs of chromosomes are shown. Which of the following phenomena is expressed?2026
- Study the pedigree chart of a family given below and answer the questions that follow: Is the disease in this pedigree chart a recessive or dominant…2023
- Study the figures given below and answer the questions. Cross - A Cross - B Identify in which of the crosses the strength of linkage between the…2026
- Inheritance of which of the following traits is shown in the cross given below? Choose the correct option from the following:2025
- If both the parents are carriers for thalassaemia, the chances of an afflicted child to be born to them is:2024
- Which of the following is correct for the condition when plant YyRr is back crossed with the double recessive parent?2025
- Which of the following features correctly show the mechanism of sex- determination in honey-bees? (i) A zygote formed from the union of a sperm and…2025
CBSE Class 12 Biology past-paper question from the 2024 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.