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.

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

Explanation:

Let W be straight wings (big letter for dominant allele)
Let w be curly wings (small letter for recessive allele)

Each fly has two alleles.
If a parent is true breeding, it only has one type of allele.
Parent 1 = WW (straight wings)
Parent 2 = ww (curly wings)

Cross the parents: WW x ww in a Punnett square (see photo below)
This is the F1 generation (generation produced by crossing the first parents).
There are only Ww offspring.

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