Plant Kingdom

• Plants


  Multicellular organisms, with cell wall made of cellulose
• Types of plants


  • Mosses
  • Ferns
  • Flowering plants
• Chlorophyll


  Pigment that absorbs energy from sunlight and produces glucose, using CO2 and H2O from environment during the process of photosynthesis
• Plant groups covered in the syllabus

  • Ferns
  • Flowering plants
• Flowering plants


  • Reproduce by seeds that are formed in flowers
  • Seeds are enclosed in an ovary

  
• Subclasses of flowering plants


  • Monocotyledons
  • Dicotyledons
• Monocotyledons


  Flowering plants that have only one cotyledon in their seeds

  
• Cotyledon


  Embryonic leaf which often contains food stores
• Monocots


  • Have long, narrow leaves with parallel leaf veins

  
• Dicotyledons (dicots)


  Flowering plants that have two cotyledons in their seeds

  
• Dicots


  • Have broad leaves with a branching network of leaf veins
• Ferns


  • Land plants with well-developed structures
  • Stems, leaves and roots are very similar to those of the flowering plants
  • Stem is usually completely below ground
  • In bracken, the stem grows horizontally below ground, sending up leaves at intervals
  • Roots grow directly from the stem
  • Have sieve tubes and water conducting cells like those in the xylem and phloem of a flowering plant
  • Leaves are several cells thick, with an upper and lower epidermis, a layer of palisade cells and a spongy mesophyll

  
• Reproduction in ferns


  1. Produce gametes but no seeds

  2. Zygote gives rise to the fern plant

  3. Fern plant produces single-celled spores from many sporangia (spore capsules) on its leaves

  4. Sporangia are formed on the lower side of the leaf, but their position depends on the species of fern

  5. Sporangia are usually arranged in compact groups