Question

A test cross is a back cross but back cross is not necessarily a test cross. Because a test cross is always between ...................

• A. F1 hybrid with another F1 hybrid
• B. F1 hybrid and recessive parent
• C. F1 hybrid and dominant parent
• D. F1 hybrid and F2 hybrid

Hint:

A test cross helps to determine the genotype of an organism showing a dominant trait by crossing it with a homozygous recessive organism.

Answer 1

The Correct Option is B

Step 1: Understanding the concept of a test cross.
A test cross involves breeding an organism with an unknown genotype (typically a dominant phenotype) with a homozygous recessive individual. This helps determine whether the dominant organism is homozygous or heterozygous.
Step 2: Analyzing the options.
(A) F1 hybrid with another F1 hybrid: Incorrect, this would not give the information needed for a test cross.
(B) F1 hybrid and recessive parent: Correct, a test cross is done by crossing the F1 hybrid with a homozygous recessive parent to determine the genotype of the F1 hybrid.
(C) F1 hybrid and dominant parent: Incorrect, this would not give the same results as a test cross.
(D) F1 hybrid and F2 hybrid: Incorrect, this is not a typical test cross scenario.
Step 3: Conclusion.
The correct answer is (B) F1 hybrid and recessive parent, as this is the definition of a test cross.