Community admins always have the authority to delete a question from their community. Also, questioners can delete their questions, only if no one has answered the question yet. Therefore, if someone gave an answer to a question, the question cannot be deleted by the questioner anymore.
If an admin deletes a question, all given answers to the questions will be deleted, and the corresponding points will be gone too.
Also, it is possible for an admin to merge one question to another similar one (Dominant Question) already exciting on the community. In this case, all the answers will be moved to the dominant question. So, if later on the original question gets deleted, all the answers and their points will remain.