Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as : -
A
Test cross
B
Reciprocal cross
C
Dihybrid cross
D
Reverse cross
The answer is B.
Solution
In a reciprocal cross, the same two parents are crossed twice, with their sexes exchanged. Example: tall (female) × dwarf (male), and dwarf (female) × tall (male). Mendel used reciprocal crosses and found the same results, showing that the traits he studied were not affected by which parent was male or female (i.e. they were not sex-linked or cytoplasmic). A test cross is a cross of an individual with a homozygous recessive parent; a dihybrid cross involves two characters. So such crosses are called reciprocal crosses.
ConceptReciprocal cross
Principles of Inheritance and Variation in past papers
198 questions from this chapter have appeared across 27 exam years.
