Question

In lathyrus odoratus, a cross between two purple flowered plants gives a pink/white progeny. It is due to,
A) Codominance
B) Incomplete dominance
C) Epistasis
D) Segregation

Answer 1

Hint: Gregor Mendel studied inheritance of behavior in pea plants. He planned a model where pairs of heritable fundamentals, or genes, specified traits. Genes come in dissimilar versions, or alleles. A dominant allele hides a recessive allele and determines the organism’s manifestation.

Complete Answer:
- The sweet pea, Lathyrus odoratus, is a flowering plant in the genus Lathyrus in the family Fabaceae. Mendel studied the genetics of pea plants and he traced the inheritance of a range of characteristics, which includes the flower color, flower position, seed color, and seed shape.
- To do so he started up by crossing pure breeding parent plants with dissimilar forms of a characteristic, such as violet and white flowers. Pure breeding which means that the plant will always make more offspring like itself when self-fertilized over lots of generations.
- The Principle of Segregation gives the idea how pairs of gene variants are separated into reproductive cells. The segregation of gene variants which are called alleles, and their equivalent traits was first observed by Gregor Mendel in 1865. Mendel has studied genetics by performing mating crosses in pea plants.
- He crossed two heterozygous pea plants that means each of the plants had two different alleles at a particular genetic position. He exposed that the traits in the offspring of his crosses did not always equal the traits in the parental plants. This means that the pair of alleles encoding the traits in each parental plant had divided or segregated from one another during the formation of the reproductive cells.
- From this data Mendel formulated the Principle of Segregation. The reason for which the purple flowered gives pink and white progeny is due to segregation. Segregation is the reason that alleles are separated during gamete formation and not blended.

So the correct answer is option D) segregation.

Note: Lathyrus sativus is used as a medicine. It is also used in Indian bread. It’s seeds are eaten as food and used as animal fodder throughout the world. The flowers of sweet peas are grown as ornamental plants for their color and fragrance.