Suppose You Are Carrying Out a Series of Crosses with an Insect

question 45

Multiple Choice

Suppose you are carrying out a series of crosses with an insect where the mechanism of sex determination is unknown.You discover a mutant female with short bristles and decide to cross it with a wild type male that has normal bristles.Half of the F₁ progeny have short bristles but all of these short-bristled F₁ progeny are males.Based on these results,a valid hypothesis would be

• A)Males are ZW,females are ZZ,and short bristles are caused by a dominant allele on the Z chromosome.
• B)Males are ZZ,females are ZW,and short bristles are caused by a recessive allele on the Z chromosome.
• C)Males are ZZ,females are ZW,and short bristles are caused by a dominant allele on the W chromosome.
• D)Males are ZZ,females are ZW,and short bristles are caused by a dominant allele on the Z chromosome.