Question

In fruit flies, straight wings are dominant and curly wings are recessive. What will the generations look like? Assume that Mendel’s method of crossing two true breeding parents with opposite traits is followed. Check all that apply.
The P generation has all straight wings.
The P generation has straight wings and curly wings.
The F1 generation has all straight wings.
The F1 generation has all curly wings.
The F1 generation has straight wings and curly wings.
The F2 generation has all straight wings.
The F2 generation has straight wings and curly wings.

Answer 1

Crossing two true breeding parents with opposite parents is the key:

Assume W is straight wing and w is curly.
Then you are crossing WW with ww
This will result in ALL Ww as offspring - so all straight offspring

If you then cross Ww x Ww you end up with a mix of 
WW (1), Ww (2) and ww (1) - so a mix of straight and curly

Answer: 
P generation has straight wings and curly wings
F1 has all straight wings
F2 has straight wings and curly wings