As a result of meiosis, quadrinucleate spermatids are formed, but only the nuclei of maternal origin produce sperm (Fig. 3).

I mean if you go in and want to challenge an exam it cost you half of your course money. If you don't pass the exam, that money is credited toward taking the course. What have you got to lose to challenge an exam, or do a competency exam?

Stop, Headstrong Muse! And e’er we Higher go, Look down, with Caution, on the Depth below; Prospects, so vast, the Rash Approacher fright, And, dazling, wound the uncollected Sight:

Even three years ago, the thought of spending two hours, let alone a whole day, without my mobile would have been anathema.