Multiple Alleles - ABO Blood Groups - Unsolved Practice Set
Chapter: Principles of Inheritance and Variation | Topic: Multiple Alleles ABO Blood Groups
MULTIPLE ALLELES - ABO BLOOD GROUPS - UNSOLVED PRACTICE SET
Topic: Multiple Alleles ABO Blood Groups
Multiple Choice Questions
Q1. Multiple alleles refer to a situation where a single gene has:
- Only two alleles in the population
- More than two allelic forms present in the population
- No alleles at all
- Alleles only found in plants
Q2. The ABO blood group system in humans is controlled by how many alleles of the gene I?
- One
- Two
- Three (IA, IB, i)
- Four
Q3. Which of the following genotypes would result in blood group O?
- IAIA
- IBIB
- IAIB
- ii
Q4. A person with genotype IAIB will have blood group:
- A
- B
- AB
- O
Q5. In the ABO blood group system, the allele 'i' is:
- Dominant over both IA and IB
- Recessive to both IA and IB
- Codominant with IA only
- Codominant with IB only
Short Answer Questions
Q6. What are multiple alleles? Why is the ABO blood group system considered an example of this?
Q7. List the possible genotypes for each of the four ABO blood group phenotypes.
Q8. Why are IA and IB alleles described as codominant with respect to each other?
Q9. Can a child with blood group O be born to parents with blood groups A and B? Explain briefly.
Long Answer Questions
Q10. Explain the concept of multiple alleles using the ABO blood group system as an example, describing all possible genotype-phenotype combinations.
Q11. Discuss how the ABO blood group system demonstrates both codominance (between IA and IB) and simple dominance (of IA/IB over i) within the same gene.
APPLICATION / ANALYSIS
Q12. A man with blood group AB marries a woman with blood group O. Work out the possible blood groups of their children, showing your reasoning based on the alleles involved.
Q13. In a hospital, a mix-up occurs and a doctor needs to verify a baby's parentage using blood groups. If the baby has blood group O, and one alleged parent has blood group AB, explain, using your understanding of ABO inheritance, why this parentage claim would be biologically impossible.