Gymnosperms

• Gymnosperm

  The "naked seed" - Exposed nature of the seed, do not have spores but a seed, their seed lack a protective enclosure
• Living phyla of Gymnosperms

  • Pinopyta (Conifers)
  • Ginkgophyta (Ginkgo)
  • Cycadophyta (Cycads)
  • Gnetophyta (Gnetophytes)
• Gymnosperms

  • Usually woody plants
  • Xylem = wood of a tree
  • Phloem = Bark of the tree
  • Their wood is formed from secondary growth
  • Alternation of generation, (2n) is dominant, (1n) is dependent
• Pinophyta (Conifers)


  Largest genus of conifers, Includes the world's oldest known living organism, Vast coniferous forest, Their leaves are needle-like and arranged in clusters (2-5 leaves each), Each cluster fasicle forms a cylindrical rod to hold the leaves together, They live in the topsoil frozen making it difficult for the roots to obtain water
• Structure of Conifer leaves

  • Epidermins - coated with a thick cuticle
  • Stomata - recessed in small cavities
  • Hypodermis - consists of one or several layers of thick-walled cell
  • Endodermis - Surround the veins and other associated tissue
• Conifer Resin Canals


  Develop in mesophyll<|>Aromatic, antiseptic, prevents the formation of fungi and deter insect attacks<|>Is used to response to injury
• Ginkgophyta (Ginkgo)


  Consist of only one species, Living fossil, The "silver apricot", Referred to as maidenhair trees because of their notched, broad, fan-shaped leaves, They are deciduous, Life cycle is similar to pines, In China and Korea it it considered as a delicacy, Clinically improves circulation and supply in vital organs, It also has effect on memory enhancement
• Cycadophyta (Cycads)


  Slow growing plants, Unbrancged trunks, Has crown of large pinnately divided leaves, Their life cycle is similar ro conifers but sometimes it brought by beetles, They are diocious
• Gnetophyta


  They're unique because theyvessels in the xylem, Their tiny leaves are produced in twos or threes at a node, Tree and branches are often whorled, Photosynthetic when they are young
• Sporophyte

  1. Megasporangium - Undergoes meiosis to produce megaspores, Female gametophyte

  2. Microsporangium - Undergoes meiosis to produce haploid, It germinates to produce male gamatephyte