
ABO blood grouping in humans is an example of
(a) Polygenic inheritance
(b)Multiple allelism
(c)Epistasis
(d)Pleiotropism
(e)Incomplete dominance
Answer
496.8k+ views
1 likes
Hint: Alleles are the pairs of genes occupying a specific spot called the locus on a chromosome. Generally, there are only two alleles for a gene in a diploid organism. It is the condition wherein three or more alleles of a gene are present.
Complete answer:
In multiple allelism, when there is a gene existing in more than two allelic forms. In general, multiple allelism is the condition wherein three or more alleles of a gene are present. Therefore, the term multiple alleles pertain to the presence of three or more alleles for a particular gene. Multiple allelism is better to understand with the help of ABO blood group system in humans. The inheritance of ABO blood group is a gene I (in which I represent isohemagglutinin) that remains in the 3 allelic expressions: , , and . and are codominant in humans. In which is responsible for type A antigens and is responsible for type B antigens, respectively, on the cell surface of erythrocytes. is a recessive allele and it does not produce antigen. If there are more than two alleles present in the population, then the individual comprising the population would possess only two such alleles. Although, the inheritance of and alleles results in having a blood type AB in the case of ABO blood group system.
Additional Information: Multiple alleles are situated on homologous chromosomes at the same locus and there is no crossing over between the members of multiple alleles. Crossing over takes place between two different genes only (i.e., inter-genetic recombination) and does not occur within a gene (intragenic recombination). Multiple alleles never show complementation with each other. With the help of the complementation test, the allelic and non-allelic genes may be differentiated well. The production of wild type phenotype in a trans-heterozygote for 2 mutant alleles is known as the complementation test.
So, the correct answer is ‘Multiple allelism’.
Note: The wild type (normal) allele is nearly always dominant while the other mutant alleles in the series may show dominance or there may be an intermediate phenotypic effect. When any of the two multiple alleles are crossed, the phenotype is of a mutant type and not the wild type.
Complete answer:
In multiple allelism, when there is a gene existing in more than two allelic forms. In general, multiple allelism is the condition wherein three or more alleles of a gene are present. Therefore, the term multiple alleles pertain to the presence of three or more alleles for a particular gene. Multiple allelism is better to understand with the help of ABO blood group system in humans. The inheritance of ABO blood group is a gene I (in which I represent isohemagglutinin) that remains in the 3 allelic expressions:
Additional Information: Multiple alleles are situated on homologous chromosomes at the same locus and there is no crossing over between the members of multiple alleles. Crossing over takes place between two different genes only (i.e., inter-genetic recombination) and does not occur within a gene (intragenic recombination). Multiple alleles never show complementation with each other. With the help of the complementation test, the allelic and non-allelic genes may be differentiated well. The production of wild type phenotype in a trans-heterozygote for 2 mutant alleles is known as the complementation test.
So, the correct answer is ‘Multiple allelism’.
Note: The wild type (normal) allele is nearly always dominant while the other mutant alleles in the series may show dominance or there may be an intermediate phenotypic effect. When any of the two multiple alleles are crossed, the phenotype is of a mutant type and not the wild type.

Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
School Full course for CBSE students
₹41,848 per year
Recently Updated Pages
Master Class 12 Business Studies: Engaging Questions & Answers for Success

Master Class 12 Economics: Engaging Questions & Answers for Success

Master Class 12 Maths: Engaging Questions & Answers for Success

Master Class 12 Biology: Engaging Questions & Answers for Success

Master Class 12 Physics: Engaging Questions & Answers for Success

Master Class 12 English: Engaging Questions & Answers for Success

Trending doubts
A deep narrow valley with steep sides formed as a result class 12 biology CBSE

Why should a magnesium ribbon be cleaned before burning class 12 chemistry CBSE

A renewable exhaustible natural resources is A Coal class 12 biology CBSE

Megasporangium is equivalent to a Embryo sac b Fruit class 12 biology CBSE

Draw a labelled sketch of the human eye class 12 physics CBSE

What is Zeises salt and ferrocene Explain with str class 12 chemistry CBSE
