Two Strains of S

Multiple Choice

Two strains of S.cerevisae (yeast) are crossed.One has the genotype A B and the other a b.Which statement correctly describes the tetrads that can be produced by one reciprocal exchange without gene conversion in the dihybrid?

A) Recombination occurs at the four-strand stage to produce a tetrad with A B, A B, a B, and a b chromosomes.
B) Recombination occurs at the four-strand stage to produce a tetrad with A B, A b, a B, and a b chromosomes.
C) Recombination occurs at the two-strand stage to produce a tetrad with A B, A b, a B, and a b chromosomes.
D) Recombination occurs at the two-strand stage to produce a tetrad with A b, A b, a B, and a B chromosomes.