Why does Melinda pass out while dissecting the frog? pages 73-92

The act of dissection reminds Melissa of her rape.

Ms. Keen's voice fades to a mosquito whine. My throat closes off. It is hard to breathe. I put out my hand to steady myself against the table. David pins her froggy hands to the dissection tray. He spreads her froggy legs and pins her froggy feet.

I have to slice open her belly. She doesn't say a word. She is already dead. A scream starts in my gut—I can feel the cut, smell the dirt, leaves in my hair.