The cell wall of algae is made up of -

A cell wall is a rigid protective layer that gives a cell its shape, and its chemical make-up differs sharply between groups of organisms: a land plant's primary wall is built mainly from cellulose reinforced with hemicellulose and pectin, while a bacterium's wall is built from peptidoglycan. Algae form a much more diverse group than either, and most algal cell walls deposit cellulose fibres within a matrix of other, algae-specific polysaccharides rather than reusing the plant or bacterial recipe.

Across many algal groups that matrix is dominated by galactans (especially abundant in red algae) and mannans (present in the walls of several algal lineages), giving the wall its characteristic cellulose-galactan-mannan composition.

This composition also distinguishes algae from the other wall types on offer:

• Cellulose, Hemicellulose and Proteins is the composition of a typical land-plant primary cell wall, not the polysaccharide matrix found in algae.

• Cellulose, Pectin and Protein is likewise a pectin-rich land-plant wall feature, not the standard algal wall.

• Cellulose, Peptidoglycan and Pectin is impossible for algae: peptidoglycan is unique to bacterial cell walls, and algae are eukaryotes that never build one.

Therefore, the composition specific to the algal cell wall is Cellulose, Galactans and Mannans.