What are the major divisions in the plantae? what is the basis for this divisions?
Answers
the formation of thier cell wall is the major part and the mode of nutrition...
Answer:
Division Bryophyta
These include mosses and liverworts.
General characteristic
They are thalloids as in liverworts or differentiated into simple-leaf like and stemlike structures
They lack vascular transport system
They contain chlorophyll hence photosynthetic.
They have developed rhizoids for anchoring and absorbing water together with dissolved mineral salts.
Show alternations of generations
Male gametes are produced by antheridia and female gametes by archegonia. Fertilisation depends on availability of water.
They are terrestrial growing on dump substratum eg rocks, walls and marshes
2. Division Pteridophyta
These include the ferns and horsetails. They show a greater variety and a greater ability than bryophyte.
General characteristics
They have roots, stems and leaves but no flowers
Leaves are compound with leaflets known as pinna.
They posses clearly defined vascular system( Having xylem and Phloem)
They show alternation of generations
Sexual reproduction
They have spirongira
Spermatophyta
3. Division Spermatophyta
This division comprises all the seed bearing plants. They are familiar green plants which produce seeds through flowers or cones.
General characteristics
The plant has roots, stems, leaves and seed bearing structures
They produce seeds
They have chlorophyll hence photosynthetic
They have vascular tissue is highly developed with xylem tissue consisting of both xylem tissue and tracheids.
The division spermatophyte consists of two main subdivisions:
Gymnosperm
Angiosperm
Characteristics
They bear cones of two types, male and female
After fertilization seeds are not enclosed in a fruit wall.
They show some xerophytic characteristics such as rolled leaves, needle-shaped leaves, sunken stomata and thick waxy leaves
Xylem consists mainly tracheids while phloem does not have companion cells