If both parents are carriers of the defective CF

gene, what is the chance that their child will have

cystic fibrosis?

o 0%

о 25%

о 50%

о 100%

-

НА В

НА

НА

и

н

на

НА

НА

- -

-

-

50%

Explanation:

Well, if you use the traditional "punnet square" method ... you would get something like this:

C F

C CC CF

F CF FF

Simply cross the genes to determine the child's genetic genes.

This is the easiest way to determine the answer.

If you are not sure how to set up the square, here you go:

First, make a table with 4 boxes.

Second, horizontally label the mother's genes across the top and the father's vertically on the side.

Then, you bring the top genes down in both boxes and the ones at the side in both boxes beside it.

...

(Make sure if you are using this method, to always put your results in alphabetical order)