Examines inheritance patterns that deviate from Mendel's laws, such as incomplete dominance, co-dominance, and traits controlled by multiple alleles. Practice questions help students recognize and analyze these exceptions.
A normal human male has 46 chromosomes, including one X and one Y sex chromosome.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Epistasis occurs when one gene suppresses the expression of another, as seen in albinism.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
A recessive allele is expressed only in individuals who are homozygous recessive (aa).
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
In codominance, both alleles contribute equally to the phenotype, as seen in the AB blood group.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
The ABO blood group system exhibits multiple allelism, involving three alleles (IA, IB, and i).
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
In codominance, both alleles contribute equally to the phenotype, as seen in the AB blood group.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
In codominance, both alleles contribute equally to the phenotype rather than one being dominant over the other.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Thalassemia is inherited in an autosomal recessive manner, requiring two mutated alleles for the disease to manifest.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Each individual inherits only two alleles for a gene, even if multiple alleles exist in the population.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Females can inherit X-linked recessive disorders if they receive two copies of the affected allele (one from each parent).
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Blood group AB is an example of co-dominance (both A and B are expressed) and multiple allelism (three alleles: IA, IB, and i).
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
Hemophilia is a sex-linked recessive disorder caused by a mutation in the X chromosome.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Non-Mendelian Inheritance - Incomplete Dominance Co-dominance Multiple Alleles
