Kingdom Plantae are large group of organisms which are primarily multicellular and photosynthetic ,some of them are unicellular as well.
Kingdom Plantae include algae, Bryophytes Pteridophytes, Gymnosperms and Angiosperms.
Algae: These are aquatic plants. The plant body is called thallus; it may be unicellular but mostly multicellular, filamentous or differentiated into holdfast, stipe, and lamina.
The algae are classified on the basis of their photosynthetic pigments and a type of reserve food.
Red algae are marine .Photosynthetic pigments are chlorophyll, phycoerythrin, and phycocyanin.They complete the life cycle in two phases-a diploid and a haploid one.
Brown algae include some of the largest type which shows differentiation in to hold fast, stipe and lamina. Accessory pigment is fucoxanthin.The cell wall is composed of phycocolloids which prevent the drying up of algae when exposed.
Green algae have chlorophyll a and b as photosynthetic pigment. Mostly fresh water, they may be unicellular or filamentous, the stored food is starch. Sexual reproduction generally involves flagellate gametes.
Bryophytes: They are primitive land plants .They include liver worts and mosses. Plant body is a gametophyte and bear antheridia and archegonia. The sporophyte is reduced. It reproduces asexually by means of spores which again give rise to gametophyte.
Pteridophytes: They are vascular but seedless plants. They possess root, stem and leaves. The plant body is a sporophyte; it reproduces asexually by spores produced inside sporangia. The spore on germination produces prothallus which is the gametophyte which produces antheridium and archegonia on them and reproduces sexually to form the sporophyte.
Gymnosperms: Seed bearing plants, do not produce flowers. Plant body is a sporophyte. Reproduction occurs by producing male and female cones.
Angiosperms: They are called flowering plants and constitute the most advanced and highly successful group. They produce seeds which are enclosed in fruits.