Which of the following is the main difference between onion peel cells and human cheek cells.

• A) The presence of mitochondria in onion peel cells only
• B) Presence of cell walls in onion cells only
• C) Absence of the plasma membrane in cheek cells.
• D) Absence of endoplasmic reticulum

The main difference between onion peel cells and human cheek cells lies in their structural components. The correct answer is:

Key Differences

• Cell Walls: Onion peel cells have a rigid cell wall, which provides structure and protection. In contrast, human cheek cells do not have cell walls; they only have a flexible plasma membrane.
• Mitochondria: Both onion peel cells and human cheek cells contain mitochondria, so option A is incorrect.
• Plasma Membrane: Both types of cells have a plasma membrane, making option C false.
• Endoplasmic Reticulum: Both cell types also possess endoplasmic reticulum, so option D is not accurate.

Therefore, the correct choice is B) Presence of cell walls in onion cells only.