Question

Differentiate between monohybrid and dihybrid cross.

Answer 1

Hint: The offspring developed by crossing, parents that differ in their characters on genetically determined traits are called hybrid. Hybrid production has helped in genetics and evolution. An offspring with many desirable characters can be introduced that has certain advantages over parents.

Complete answer:
The offspring or progeny developed when cross is made between parents that differ in their genetic traits or characters either phenotypically or genotypically is called a hybrid.

Monohybrid cross	Dihybrid cross
(1) Mono-one, hybrid-mixing of breeds or cross.	(1) Di-two; Hybrid-mixing of breeds or cross.
(2) A cross between parents that differ in a single trait or characteristics is called a monohybrid cross.	(2) A cross between parents that differ in two alleles or traits or character is called a hybrid cross.
(3) The progeny obtained from monohybrid cross is called monohybrid species.	(3) The species obtained from dihybrid cross is called dihybrid species.
(4) It is used to study inheritance of a single pair of alleles.	(4) It is used to study inheritance of two different alleles.
(5) It is used to study the dominance of species.	(5) It is used to study offspring assortment.
(6) The genotypic ratio is: 1:2:1	(6) Phenotypic ratio is 1:2; 1:2; 4:2; 1:1
(7) Phenotypic ratio is : 1:1	(7) Genotypic ratio is 9:3:3:1
(8) The cross test ratio is 1:1	(8) Test cross ratio is 1:1:1:1

Note:The main use of dihybrid cross is to determine if a relationship existed between different allelic pairs. Whereas, the use of monohybrid cross is to determine the dominance of relationship between two alleles.