Genetic testing of an F1 hybrid Crossing an F1 individual with a homozygous recessive tester is referred to as which type of cross?

Introduction / Context:
Breeders and geneticists use specific crosses to reveal genotype. A test cross helps determine whether an individual with a dominant phenotype is homozygous dominant or heterozygous.

Given Data / Assumptions:

• F1 is typically heterozygous when derived from two true-breeding parents.
• The tester is homozygous recessive for the locus of interest.

Concept / Approach:
In a test cross, mating with a homozygous recessive reveals the gametes contributed by the tested parent, because the tester contributes only recessive alleles. Offspring phenotypes therefore directly reflect the tested parent’s genotype.

Step-by-Step Solution:

Verification / Alternative check:
Any genetics manual describes test crosses for mapping and genotype assessment.

Why Other Options Are Wrong:

• “Recessive cross” is not standard terminology.
• “Criss-cross” refers to sex-linked transmission patterns, not this cross.
• “Para-cross” is not a standard genetic term.
• Backcross to a dominant parent is a different design and does not reveal hidden recessive alleles.

Common Pitfalls:
Confusing backcross (to either parent) with a test cross (specifically to recessive).

Final Answer:
Test cross