Must one make up prayers that were performed without ghusl for janabah, while being aware of the احتلام (wet dream) but ignorant of the ruling?

If it is merely doubt and whisperings (waswasah), do not pay it any attention. However, if you are certain that semen was discharged and you did not perform ghusl (definition) (ritual bath), then your prayer is not valid, and you must make it up due to the absence of the condition of purity. If you were ignorant of the obligation of ghusl at that time, some scholars hold the view that you are not required to repeat the prayers you performed before knowing the ruling. It is permissible for a person afflicted by waswasah to adopt this opinion. As for fasting while in a state of janabah (definition) (major ritual impurity), it is valid, and you are not required to make it up, because purity is not a condition for fasting.