General Characteristics of Kingdom Plantae
- They are multicellular and eukaryotic.
- They are photosynthetic and have pigment chlorophyll.
- Their cells have cellulose cell walls.
- They reproduce sexually, others asexually.
- Kingdom Plantae has three major divisions:
- Bryophyta,
- Pteridophyta
Division Bryophyta
These include mosses and liverworts.
- Plant body is not differentiated into root, stem and leaves.
- They have simple structures which resemble leaves and stems.
- They have rhizoids for absorbing water and anchoring the plant to substratum.
- Life cycle consists of two morphologically different plants, the gametophyte and sporophyte.
- The two alternate.
- They show alternation of generations.
- The gamete producing gametophyte is the persistent plant.
- The sporophyte is attached to the gametophyte and is nutritionally dependent on it.
- They lack vascular system.
- Sexual reproduction is dependent on water.
Division Pteridophyta:
These include ferns and horsetails.
General Characteristics
- They have root and shoot system.
- Leaves are compound known as fronds, they have a vascular system.
- They show alternation of generations whereby the spore bearing sporophyte is the main plant.
- Spores are borne in clusters on the underside of leaves making sari.
- The gametophyte is an independent minute structure called prothallus which is short lived.
- Sexual reproduction is dependent on water.
Division Spermatophyta
These are the seed bearing plants.
General Characteristics
- Plant body is differentiated into root, stem and leaves.
- Vascular tissue consists of xylem and phloem.
- Sexual reproduction is independent of water.
- Male gametophyte (pollen grain) germinates and grows to reach female gametophyte.
- They are divided into two sub-divisions:
- Gymnosperms
- Gymnosperms
- These are cone-bearing plants.
- Naked seeds.
- They are trees and shrubs.
- Xylem consists of tracheids only.
- Examples; pine, cypress and spruce.
- They show xerophytic characteristics like having needle-like leaves. Angiosperms
- Seeds are enclosed within a fruit.
- They comprise trees, shrubs and herbs.
- Xylem consists of vessels of tracheids.
- These are the most advanced plants.
- Angiosperms has two classes;
- Monocotyledonae
Comparison of Dicotyledonae and Monocotyledonae
Economic Importance of Spermatophyta