Describe a simple lab method to observe plant cells using onion epidermis and methylene blue stain.

• A. Peel a thin layer of onion epidermis, place on slide with a drop of methylene blue, gently cover with a coverslip, and observe under a light microscope.
• B. Boil onion and mash; stain with iodine; observe under X-ray.
• C. Peel onion and place in ethanol; observe without staining.
• D. Use methylene blue to stain animal cells in saliva.

Answer: (A)