Cystic fibrosis (cf) is caused by a recessive allele. a couple who do not have cf have a child that has cf. what is the probability that if they have another child, that the child will be heterozygous for cf?

50% but some times that child be comes a carrier. it is hard to explain even for me. i have it and i only know a little, so to help you out, here is an image.

hope this helps

Ibelieve the answer is relative humidity  because it makes more sense that way. solar flares usually occur in space it doesn't affect the earth, well it could but it wont make a significant damage.  latitude is land it doesnt do anything. prevailing winds, i dont know the correct meaning for this but i doubt that affects the land so it has to be relative humidity.