IB DP Biology: SL复习笔记5.2.3 Plant Phyla Features

Plant Phyla Features

  • All plants belong to the plant kingdom
  • Within the plant kingdom are several phyla (singular phylum)
  • Some plant phyla are small
    • E.g. the Glaucophytes contain only 70 species and the Gingkophytes contains only 1 living species
  • There are four major plant phyla
    • Bryophytes (20 000 species)
    • Filicinophytes (10 000 species)
    • Coniferophytes (600 species)
    • Angiospermophytes (352 000 species)
  • Each of the four main phyla can be identified by their characteristics

Bryophytes

  • The bryophytes include mosses, liverworts, and hornworts
  • They are small, terrestrial plants
  • They have no vascular tissue
  • Cambium tissue is also absent
    • Cambium is a tissue containing stem cells that differentiate into xylem and phloem cells
  • Reproduction takes place via spores
    • Spores are produced in and dispersed from spore capsules
  • Bryophytes do not produce flowers, pollen, ovules, seeds, or fruits
  • No true roots are present, but hair-like structures called rhizoids anchor plants in the soil

5.2.3-Plant-Phyla-Features

The bryophytes include mosses and liverworts

Filicinophytes

  • Filiconophytes are the ferns
  • Ferns are mainly terrestrial and have vascular tissue
  • Roots, stems, and leaves are present
    • Fern leaves are divided structures known as fronds
  • Cambium tissue is absent
  • Reproduction takes place via spores
    • Spores are produced in and dispersed from structures on the underside of fronds called sporangia
  • Filicinophytes do not produce flowers, pollen, ovules, seeds, or fruits

The-filicinophytes

The filicinophytes are the ferns

Coniferophytes

  • More commonly referred to as the conifers, the coniferophytes are usually tall, straight, trees
  • Roots, stems, and leaves are present
  • Vascular tissue is present, as well as cambium tissue
  • Reproduction is carried out via pollen and ovules
    • Pollen is produced in male cones and ovules are produced in female cones
      • Pollen is the male gamete and ovules are the female gamete
    • No flowers are present
    • Both male and female cones are present on each tree
    • Pollen is carried from one cone to another by the wind in order for fertilisation to take place
  • Seeds develop after fertilisation inside cones and are dispersed by falling to the ground or by animals
  • Most coniferophytes are evergreen (i.e. they retain their leaves all year round)

Coniferophytes-reproduce-via-pollen-and-ovules

Coniferophytes reproduce via pollen and ovules that are produced inside cones

Angiospermophytes

  • Often referred to as angiosperms, these are flowering plants
  • This is an incredibly diverse phylum, with examples including grasses, shrubs, and non-coniferous trees
  • Roots, stems, and leaves are present
  • Vascular and cambium tissues are present
  • Reproduction is carried out via pollen and ovules
    • Flowers produce pollen and also contain ovules within an ovary
    • Fertilisation occurs when pollen is transferred from one flower to another by e.g.
      • Insects
      • Animals
      • Wind
    • Seeds form and are dispersed via fruits which develop from the ovaries of flowers

Angiospermophytes

Angiospermophytes reproduce via pollen and ovules produced in flowers

Plant Phyla Features Table

Plant-Phyla-Features-Table

 

 

 

 

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