Biology Inheritance / Variation & Genetics UHS 2023
PMDC Verified Question 38 of 94
ABO blood group is controlled by more than two alleles in a population. This shows that ABO blood group is an example of:
A
Polygenic Inheritance
B
Multiple alleles
C
Operons
D
Allelic interaction
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Multiple alleles
Concept:

While a diploid individual only holds two alleles for a single gene, the overall population may contain many variants of that gene.

Solution:

  • The ABO blood group system is governed by a single gene locus (Gene I).
  • However, it exists in three different allelic forms within the human population: \(I^A\), \(I^B\), and \(i\).
  • Because it is controlled by more than two alternative alleles, it is a classic example of multiple alleles.


Why other options are incorrect:

  • Polygenic inheritance: Occurs when multiple different genes (often on different chromosomes) control a single trait (e.g., skin color). ABO is one gene, multiple alleles.

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