Question

Hinny and mule are examples of
a) Test cross
b) Dihybrid cross
c) Back cross
d) Reciprocal cross

Answer 1

Hint: Crosses are done in order to know the genotype and phenotype of the offspring produced by the parent variety. Mendel performed monohybrid and dihybrid cross on the pea plant. Hinny and mule are also the results of the cross performed on their parents.

Complete answer:
The hinny and mule are the offspring produced by the cross done by their parents. The cross performed on them was a reciprocal cross. In this type of cross, the sex of the parent is not important. One variety of males can be crossed with the other variety of females and vice versa. Hinny is produced by the cross between the female donkey and the male horse. The mule is produced by the cross between the male donkey and female horse. Both are formed from the donkey and horse as their parents. Reciprocal crosses yield sterile offspring and they cannot reproduce to produce more progenies of their kind. Hinny and mule have both the characteristics of donkey and horse.

Additional information:
The test cross is done between the offspring and the recessive parent. This helps in the determination of the genotype of the offspring. The genotype of the offspring can be either homozygous dominant or heterozygous dominant. The dihybrid cross is the cross made between the two traits of the same plant. For example, Mendel used the seed shape and colour in the dihybrid cross. Back cross is performed when the offspring is crossed with either recessive parent or dominant parent.

So, the answer is ‘reciprocal cross’.

Note: The hinny and mule are produced by the breeding of donkeys and horses. In the reciprocal cross, the offspring produced is not capable of producing its own progeny and is sterile. The advantage of the reciprocal cross is that the sex of the parent is not necessary for this type of cross.