The way you know the subject of the (series of words that make sense and that have a subject and a verb) is plural is because it takes a plural verb. You can see that the subject of the (series of words that make sense and that have a subject and a verb) is the ova (plural for of Latin word ovum, meaning egg cell), and the verb it takes is go through (plural), and not goes through, which would be amazing/surprising (or: single).