F₁ heterozygote of a dihybrid cross, when test crossed with a homozygous recessive parent, produces offspring in the ratio 1 : 1 for the two parental types. Which interpretation is correct?
(1) The genes of the two traits are complementary.
(2) Such a result is not possible.
(3) The genes in the cross are completely linked.
Choose the correct answer from the codes given below:

Correct option is C

Correct Answer: (c)
Explanation:
A 1 : 1 ratio of only parental phenotypes in a test cross indicates complete linkage, meaning no recombination occurred.
Information Booster:
Independent assortment yields 1 : 1 : 1 : 1, not 1 : 1.
Linkage reduces or prevents recombination.
Complete linkage = 0% recombination frequency.
Observed first by Morgan in Drosophila.
Linked genes are inherited together.
Additional Information (Incorrect Statements):
(1) Complementary genes refer to gene interaction, not linkage.
(2) The result is possible under complete linkage.