Question

Which of the following is the main difference between onion peel cells and human cheek cells?
A: Presence of mitochondria in onion peel cells only
B: Presence of cell wall in onion peel cells only
C: Absence of plasma membrane in cheek cells
D: Absence of endoplasmic reticulum

Answer 1

Plant cell contains cell wall whereas cell wall is absent in animal cells. Animal cells only contain cell membranes while plant cells have both cell walls and cell membranes. Also, the plant cell contains chloroplast which is absent in animal cells.

Complete answer: Onion peel cells are plant cells and the human cheek cells are animal cells. Animal cells are devoid of two organelles i.e. cell wall and chloroplast. Other differences between animal and plant cells are size - Plant cell > Animal cell. Plant cells are comparatively greater than animal cells. Plant cells have a large central vacuole which is used for storage and maintaining the shape of the cell whereas animal cells have small temporary vacuoles. Both plant and animal cells have mitochondria, but only plant cells have chloroplasts because of which photosynthesis takes place in plant cells. As a by-product of photosynthesis sugar is made, which is broken down by the mitochondria to release energy for the cell. In-plant cells storage is done as starch whereas in animals it as glycogen. Plant and animal cells are different from each other. The main difference between plant and animal cells is that plant cells have a cell wall as the outer layer, whereas animal cells only have a cell membrane. The cell wall is a protective layer outside the cell membrane that also provides support for the cell's structure. The cell wall is made up of cellulose.

Hence, the correct option is (B).

Note: Plant cells have a cell membrane and a cell wall and animal cells have cell membrane simply but no cell wall. In plants, this cell wall surrounds the cell membrane which gives a unique rectangular shape to the plant cell.