Question

How we consider green algae similar to the plant world.

Answer 1

Algae are chlorophyll bearing, simple, thalloid, autotrophic, and largely aquatic(both freshwater and marine) organisms. They live in moist stones, soils, and wood. Algae are divided into three main classes: Chlorophyceae(Green algae), Phaeophyceae(Brown algae), Rhodophyceae(Red algae).

Complete answer: The members of Chlorophyceae are commonly called green algae. Green algae body may be unicellular, colonial, or filamentous. Green algae lack roots, leaves, and stems but they have chloroplast plastid that contains a green pigment called chlorophyll a and b that trap light energy which is used during photosynthesis. Algae bear chlorophyll so it also makes food. This is the main characteristic of algae that is similar to plants. Algae are the main producer in aquatic habitats. Some examples of chlorophyll are Chlamydomonas, Volvox, Spirogyra and Chara. The other reason is that green algae have a rigid cell wall made up of an inner layer of cellulose and an outer layer of pectose. Hence, due to the presence of chlorophyll and cell wall, the green algae is classified under the plant kingdom.
Additional Information:

Type of algae	Common Name	Cell wall
Chlorophyceae	Green algae	Cellulose
Phaeophyceae	Brown algae	Cellulose and algin
Rhodophyceae	Red algae	Cellulose, pectin, and polysulphate esters

Note: The chloroplast in green algae may be discoid, plate-like, reticulate, cup-shaped, spiral, or ribbon-shaped in different species. Most of the members have one or more storage bodies called pyrenoids located in the chloroplasts. Pyrenoids contain protein besides starch. The green algae reproduce by vegetative propagation, asexual, and sexual mode. Asexual reproduction takes place with the help of spores.