A child has blood group O. If the father | Class 12 Biology Chapter Principles of Inheritance and Variation, Principles of Inheritance and Variation NCERT Solutions

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Academic session 2026-27, Chapter 4 in the current curriculum.

Welcome to the NCERT Solutions for Class 12 Biology - Chapter Principles of Inheritance and Variation. This page offers a step-by-step solution to the specific question from Exercise 1, Question 12: A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.. With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 12: A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.
Answer:

The blood group characteristic in humans is controlled by three set of alleles, namely, IA, IB, and i. The alleles, IA and IB, are equally dominant whereas allele, i, is recessive to the other alleles. The individuals with genotype, IA IA and IA i, have blood group A whereas the individuals with genotype, IB IB and IB i, have blood group B. The persons with genotype IA IB have blood group AB while those with blood group O have genotype ii.

Hence, if the father has blood group A and mother has blood group B, then the possible genotype of the parents will be

Father Mother

IA IA or IA i IB IB or IB i

A cross between homozygous parents will produce progeny with AB blood group.

progeny with AB blood group

A cross between heterozygous parents will produce progenies with AB blood group (IAIB) and O blood group (ii).

progenies with AB & O blood group

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Comments

  • Srishti
  • Jun 13, 2019

Thank you

  • alanor george steward
  • Mar 27, 2019

thank u.......

  • alanor george steward
  • Mar 27, 2019

thanks .... seriously this is the very important question .....perhaps this question is being continuously asked for about 5 yrs........

  • Deepak
  • Mar 08, 2019

😀thank u

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Welcome to the NCERT Solutions for Class 12 Biology - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 12: A child has blood group O. If the father has blood group A and mother blood group B, work out the ge....

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