Plantae: Plant Kingdom | Biology for JAMB PDF Download

Classification

• The plant kingdom is divided into five major divisions: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, and Angiosperms.
• Thallophyta includes algae and fungi-like organisms.
• Bryophyta consists of non-vascular plants such as mosses and liverworts.
• Pteridophyta comprises vascular plants that reproduce via spores, including ferns and horsetails.
• Gymnosperms are seed-bearing plants with naked seeds, such as conifers.
• Angiosperms are flowering plants with enclosed seeds and are the most diverse group of plants.

Characteristics

• Plants are multicellular eukaryotes with cell walls made of cellulose.
• They possess chloroplasts containing chlorophyll for photosynthesis.
• Most plants exhibit alternation of generations, having a haploid gametophyte and a diploid sporophyte stage.
• Plants have specialized tissues for transport (xylem and phloem) and support (stems, roots, and leaves).
• They reproduce sexually through the production of gametes, and some can also reproduce asexually.

Algae

• Algae are photosynthetic organisms found in diverse habitats like freshwater, marine environments, and moist soil.
• They range from single-celled to multicellular forms.
• Examples include green algae, brown algae, red algae, and diatoms.

Bryophytes

• Bryophytes are non-vascular plants that lack true roots, stems, and leaves.
• They require a moist environment for reproduction because they depend on water for fertilization.
• Mosses and liverworts are common examples of bryophytes.

Pteridophytes

• Pteridophytes are vascular plants that reproduce via spores.
• They have true roots, stems, and leaves.
• Ferns, horsetails, and clubmosses are examples of pteridophytes.

Gymnosperms

• Gymnosperms are seed-producing plants in which seeds are not enclosed in fruits.
• They have well-developed vascular tissues.
• Conifers, cycads, and ginkgoes are examples of gymnosperms.

Angiosperms

• Angiosperms are flowering plants with seeds enclosed in fruits.
• They have highly evolved reproductive structures, including flowers and fruits.
• Angiosperms are further classified into monocots and dicots based on the number of cotyledons in their seeds

Fig. Classification of Plant Kingdom