1. (10 points) You are studying wing colour in a newly discovered type of butterfly. The ZW system is used in butterflies, where males are Z/Z and females are Z/W. You have two different populations of pure-breeding butterflies. One population has orange and black wings and the other has solid orange wings.
b) What does pure-breeding mean? (1 point)
You do a pair of reciprocal crosses with your two populations. CROSS A involves black and orange females crossed to solid orange males. All the F1 offspring of cross A have solid orange wings.
c) What have you learned from this cross? (1 point)
CROSS B involves a solid orange winged female and a black and orange male.
d) Predict the outcome expected if the wing colour trait is sex-linked. Use defined symbols of your choice in your explanation. (2 points)
e) Predict the outcome expected if the wing colour trait is autosomal. Use defined symbols of your own choice (2 points)
f) If the trait is sex-linked, predict the offspring expected if the F1 from cross B (described in part d, above) are interbred. (2 points)
1. (10 points) You are studying wing colour in a newly discovered type of butterfly. The ZW system is used in butterflies, where males are Z/Z and females are Z/W. You have two different populations of pure-breeding butterflies. One population has orange and black wings and the other has solid orange wings.
b) What does pure-breeding mean? (1 point)
You do a pair of reciprocal crosses with your two populations. CROSS A involves black and orange females crossed to solid orange males. All the F1 offspring of cross A have solid orange wings.
c) What have you learned from this cross? (1 point)
CROSS B involves a solid orange winged female and a black and orange male.
d) Predict the outcome expected if the wing colour trait is sex-linked. Use defined symbols of your choice in your explanation. (2 points)
e) Predict the outcome expected if the wing colour trait is autosomal. Use defined symbols of your own choice (2 points)
f) If the trait is sex-linked, predict the offspring expected if the F1 from cross B (described in part d, above) are interbred. (2 points)
