Question

When F1 individuals cross with either of the two parents. Then it is known as
A) Test cross
B) Back cross
C) Reciprocal cross
D) Monohybrid cross

Answer 1

Hint: The offspring obtained from the cross between the parents make the F1 or first filial generation. The members of the F1 generation are heterozygous. The F1 generation expresses the dominant trait. The cross between the members of F1 generation produces F2 generation.

Complete answer:
To answer this question, we must know about different types of cross given in the question.
Test cross: It is a cross between an organism of which the genotype is not known with a parent showing recessive traits. It is used for determining whether the offspring is homozygous or heterozygous for a particular trait.

Back cross: It is a cross between the F1 generation heterozygous hybrid to one of the parents. It is done in order to get offspring which are genetically identical or closer to the parent. It is useful in horticulture, in breeding animals or to obtain gene knockout organisms.

Reciprocal cross- It is a cross in which cross is made between parents (A and B) and using them as female and male parent in turn so as to obtain two reciprocal cross A X B and B X A.

Monohybrid cross- It is a cross between the parents which involves a single observable trait. The F1 generation obtained is the hybrid of the parent.

Thus, the correct answer is option ‘B’.

Note: Back cross is used to obtain pure lines. The back cross is an easier method for crop improvement. Desirable traits of the parents are introduced to the offspring by the help of subsequent back cross.