I told you before that if you get a question that you REALLY don't know anything about, yuo should answer anyway. And why I tell you this is because it happened to me. The professor asked me: So tell me about the eyes.
My brain was working and working all over again...the eyes? eh... C'mon Bella you know a lot about the eyes! Guys, maybe you don't get it now, but when you sit there in front of the professor you get mind-blowed. It feels like you don't know anything anymore! By breathing, smiling, you will get control of yourself again..and so did I ... Since I hadn't studied about the eyes for this exam I started to tell him everything I generally knew about the eyes. This was my answer.
Me: I draw an eye on a paper, and draw the pupil, the iris, the lens and the vitreous humor. And I started to explain in this way (I know that some things may sound really stupid since even children know these things, but it's better to tell them everything you know then nothing!). "Well Professor, we can see with the eye, we see light, darkness and colors. The eye is an organ. The eyes sees the light and convert it into electro chemical impulses in neurons. When it has convert the signals into impulses in the neurons it transmits these signals to the brain, to a place called visual cortex. Many people have problems with the eyes. They see less then others."
And that was it...that was everything I knew about the eye. And I saw the professor writing on a paper, I saw that he had actually given some points to me for this answer. So remember, it's better that you tell the professor everything you know, and received some points, instead of not telling the professor since you think it's not good enough fact and you receive 0 points.