Answer: Can you zoom in or type it out? I cannot see the words.
Explanation:
Formal principle because formal means "used to be" so the ex principal would be the FORMER principal. he's not principal.
The way you know the subject of the sentence is plural is because it takes a plural verb. You can see that the subject of the sentence is <em>the ova </em>(plural for of Latin word <em>ovum</em>, <em />meaning egg cell), and the verb it takes is <em>undergo </em>(plural)<em>, </em>and not <em>undergoes, </em>which would be singular.