Principles of Inheritance and Variation Question 48
48. Test cross involves
[2006]
(a) crossing between two $F_1$ hybrids
(b) crossing the $F_1$ hybrid with a double recessive genotype
(c) crossing between two genotypes with dominant trait
(d) crossing between two genotypes with recessive trait
Show Answer
Answer : b
Hints & Solution
(b) A cross of $F_1$ hybrid with its recessive homozygous parent is called the test cross. It is done to determine the genotype of a given plant. If the given plant has homozygous dominant traits then on test cross it gives all dominant trait plants but if it is heterozygous dominant then it gives dominant and recessive phenotypes in $1: 1$ ratio.
