Question

a scientist is studying fruit fly wings. straight wings are dominant, and curly wings are recessive. which statement correctly describes the f₁ generation if a straight - winged parent is crossed with a curly - winged parent and if both parents are true breeding?

○ the offspring will have two genes for straight wings.
○ the offspring will produce only gametes that have genes for curly wings.
○ the offspring will have one allele for straight wings and one allele for curly wings.
○ the offspring will have only one kind of allele for the gene that determines wing type.

Explanation:

1. True - breeding straight - winged (dominant) parent has genotype \(SS\) (homozygous dominant), curly - winged (recessive) parent has genotype \(ss\) (homozygous recessive).
2. When crossed (\(SS\times ss\)), all \(F_1\) offspring get one \(S\) (from straight - winged parent) and one \(s\) (from curly - winged parent), so genotype \(Ss\).
3. Analyzing options:

• Option 1: Offspring have \(Ss\), not two straight - wing genes. Wrong.
• Option 2: \(Ss\) produces \(S\) and \(s\) gametes, not only curly. Wrong.
• Option 3: \(Ss\) has one \(S\) (straight) and one \(s\) (curly) allele. Correct.
• Option 4: \(Ss\) has two different alleles. Wrong.

Answer:

The offspring will have one allele for straight wings and one allele for curly wings.