Question

Which one of the following is an example of polygenic inheritance?

• A. Flower colour in Mirabilis jalapa
• B. Production of male honey bee
• C. Pod shape in garden pea
• D. Skin colour in humans

Answer 1

The correct option is D Skin colour in humans

Polygenic inheritance occurs when one character is controlled by two or more genes. Often the genes are large in number but small in effect. Examples of human polygenic inheritance are height, skin color.

The pink flower colour in Mirabilis jalapa is an example of incomplete dominance. Incomplete dominance is a form of intermediate inheritance in which one allele for a particular trait is not expressed completely over its paired allele resulting in intermediate phenotype. In flower colour of Mirabilis jalapa, pink colour flower is produced due to incomplete dominace of red colour over white colour.

Production of male honey bees is an example of parthenogenesis. Parthenogenesis refers to the development of an egg or ovum into an offspring without undergoing fertilisation. In bees, the unfertilised eggs carrying haploid (n) number of chromosomes develop into male drone bees.

Pod shape of garden pea is controlled by a single gene.