This is a essay question teacher say we can use external help to answer the question. Anyone help? Thanks

Consider two people that are both heterozygous for the recessive disease Cystic Fibrosis
(F is the normal allele, f is the diseased allele)
a. Draw a Punnett square that shows the inheritance patterns of their offspring.
b. What are the possible genotypes of the offspring?
c. What are the possible phenotypes of the offspring?
d.What is the probability (percentage) that their child will be a carrier of the disease?

I will help you because I had students from the same family with CF in one sibling, who passed away at the age of 15, and I counseled her parents and her siblings on how this works. Her siblings were tested and one was a carrier, one was not.
Ok..using the Punnett square, remembering that this is not a sex-linked characteristic, so we need the genotypes of both parents:
Both parents are normal but are carriers, so they are heterozygous, Ff. Here is the square:

F f

F FF Ff

f Ff ff

The possible genotypes are 25% chance of FF (non carrier), 50% chance of Ff (normal but carrier) and 25% of ff, CF person, homozygous recessive.
The possible phenotypes are 75% normal, 25% CF
As you can see, I've already given you the percentages, but to be sure, there is a 50% chance of having a carrier each time this couple has a child.

b: FF, Ff and ff.
c: Havind the disease (ff) and not having the disease (FF and Ff)
d: 25% (sice the possibel genotypes from the punnett square are FF, Ff, Ff again and ff.)

Hope I helped =)