Question

Identify the incorrect statements:
i) Multiple alleles are produced due to repeated mutation of the same gene but in different directions.
ii) In co-dominance, both the alleles of the gene are dominant and express independently in the heterozygous condition.
iii) Incomplete dominance results in two different phenotypes in the hybrid.

• A. Statements ii and iii
• B. Statement iii only
• C. Statement i only
• D. Statements i and ii

Answer 1

The correct option is B Statement iii only

Incomplete dominance does not result in two different phenotypes, rather an intermediate phenotype is seen in the hybrid.

For example, in dog flower (Antirrhinum), the cross between red and white-flowered plants produces pink-flowered plants.


Multiple alleles exist in a population when there are many variations of a single gene. These are produced due to repeated mutations of the same gene in different directions in the population. Example - 3 alleles for ABO blood groups in humans, 4 alleles for coat colour in rabbits etc.

In co-dominance, both the alleles of the gene are dominant and are expressed independently in the heterozygous condition. For example, the cross between shorthorn cattle of red and white coat colour produces roan coat (patches of red and white) cattle.