Kyle concludes that the cell must be a plant cell. how does kyle know that the cell is a plant cell and not an animal cell?

Kile should know the answer because of the morphology (part of biology that studies the estructure and the form of something). The plant cell presents a rectangular form, while the animal's cells presents a round form.

There are other main differences. As their parts and the size. Before I explain that remember that a cell can be of two types eukaryotic (cell with nucleus) and prokaryote (cell with no nucleus). In the other they can be neurons, nefrons, etc...

The plant cell contains for example chloroplasts, cell wall and vascuoles; while animal's don't.  Both of them have nucleus, cell plants are generally larger than animals. Those are the main differences.

Thankyou.

Sorry for my bad english, It's not my native language.