Question

Outermost layer of cell wall is

• A. plasma membrane
• B. secondary wall
• C. middle lamella
• D. primary wall

Answer 1

The correct option is D primary wall

The primary wall is the first layer of the cell wall and is mainly made up of cellulose and hemicellulose in plants. It is formed inner to the middle lamella and is typically found in young cells. This then gets either replaced or the secondary wall is added inside it towards the cell membrane.

The cell membrane or plasma membrane is the outermost layer of an animal cell, while in plant cells, it lies inner to the cell wall.

The middle lamella is the common layer that connects all the cells. This is the first formed layer during cytokinesis (division of the cytoplasm).