Question

Algae has walls made up of
A. Cellulose, Galactose and mannose
B. Hemicelluloses, Pectin, and Proteins
C. Pectin, Cellulose and Proteins
D. Cellulose, Hemicelluloses and Pectin

Answer 1

Hint: Algae is a widely used terminology to describe a group of organisms that are eukaryotic and are capable of producing their own food. So, it includes both green algae and blue algae( i.e. cyanobacteria that is a member of Kingdom Monera).

Complete answer:
First of all let us discuss a little about green algae,
Algae are the chlorophyll bearing aquatic organisms that are simple, thalloid and autotrophic in nature. Green is algae is a member of class Chlorophyceae. They exist in a variety of habitats.
Now coming on to the cell wall of plants, first we will discuss the land plants.
The cell wall of the plants that exist on the land is normally and basically composed of the polysaccharides such as cellulose, hemicelluloses and pectin.
Next we will discuss about the cell wall of the algae,
The cell wall of green algae (Chlorophyceae) is made up of cellulose.
And the cell wall of brown algae (Phaeophyceae) is composed of Cellulose and algin.
Now at last, the cell wall of red algae (Rhodophyceae) is composed of cellulose, pectin and polysulphate esters. Some of the red algae have a cell wall that is made up of mannan fibrils or xylan fibrils.
Now let us see about the blue algae, its cell wall is made up of peptidoglycan layer.
Galactans are also present in the cell wall of algae.

So the correct option is (A).

Note:
Kindly note that the composition of cell walls of different classes of algae is different. Also cellulose is absent in Chlamydomonas and Volvox where the cell wall is made up of glycoproteins and polysaccharides.