Concept:Inheritance patterns include incomplete dominance, co-dominance, pleiotropy, and polygenic inheritance, each identified by specific examples.
Key Fact:Incomplete dominance produces an intermediate phenotype; co-dominance expresses both alleles equally; pleiotropy causes multiple effects from a single gene; polygenic inheritance involves multiple genes.
Explanation:Incomplete dominance occurs in flower colour of
Antirrhinum (snapdragon), where red and white parents produce pink offspring.
Co-dominance is seen in ABO blood groups; individuals with genotype
IAIB express both A and B antigens.
Pleiotropy is exemplified by phenylketonuria, where one gene defect leads to mental retardation, lighter skin, and other symptoms.
Polygenic inheritance controls human skin colour, influenced by multiple gene pairs such as
MC1R.
Thus, the correct matching is: A (Incomplete dominance) → II (Antirrhinum flower colour), B (Co-dominance) → IV (ABO blood groups), C (Pleiotropy) → III (Phenylketonuria), D (Polygenic inheritance) → I (Human skin colour).
Answer:Option A: A-II, B-IV, C-III, D-I.
