Question

A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of geneA; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine.

A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type):

What is the greatest benefit of having used a testcross for this experiment?

A) The homozygous recessive parents are obvious to the naked eye.
B) The phenotypes of the progeny reveal the allelic content of the gamete from the heterozygous parent.
C) The homozygous parents are the only ones whose crossovers make a difference.
D) All of the progeny will be heterozygous.
B) The phenotypes of the progeny reveal the allelic content of the gamete from the heterozygous parent.

Answer 1

Answer:

B- The phenotype of the progeny reveal the allelic content of the gamete from the heterozygous parent.

Explanation:

Normally, such tests are used to identify the allele content of the parent, to determine the gene dominance and recessiveness. That is, which gene is dominant ,and which is recessive. These would enable easier mapping of  traits of newly found species.