Characteristics

1
Characteristics

• Unlike mosses, ferns are larger, more complex,
  and grow more independently. Live in damp shady
  places
• Multi-branched leaves called fronds (3-10 mm
  long)
• On the underside of the leaves are spots called
  sori, which are clusters of sporangia

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
2
Characteristics

• Vascular tissue Xylem and Phloem
• Xylem-conducts most water and minerals, includes
  tracheids, tube-shaped cells that conduct water
  and minerals from roots
• Phloem-cells arranged in tubes that conduct
  sugars, amino acids, and other organic products
• Spores instead of seeds or flowers.
• Sporangia-a capsule where haploid spores develop
  after meiosis has occurred

Sporangium
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3
History

• Plantae -gt Pteridophyta
• Classes Marattiopsida, Osmundopsida,
  Gleicheniopsida, Pteridopsida
• Estimated 20,000 species of ferns
• Evolved from green algae
• First appeared in early-Carboniferous after
  lycophytes
• The "great fern radiation" during late-Cretaceous
  before seeding plants

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
4
Life-cycle of Pterophyta

• Haploid spores released from sporangia and are
  dispersed

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5
Life-cycle of Pterophyta

• Fern spore develops into a photosynthetic
  gametophyte

Gametophyte
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6
Gametophyte

• On the underside of the gametophytes are the
  antheridia and archegonia
• The motile sperm are released from antheridia and
  swim (flagella) to fertilize eggs in archegonia

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7
Life-cycle of Pterophyta

• A zygote develops into a sporophyte
• The zygote grows out from the archegonium of its
  parent, the gametophyte

• Sporophyte
• Gametophyte

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
8
Life-cycle of Pterophyta

• On the underside of the adult sporophytes
  reproductive leaves are spots called sori,
  clusters of sporangia

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
9
Sporangia

• Inside a sporangium meiosis occurs and produces
  haploid spores
• After being released from sporangia, the spores
  will develop into gametophytes

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
10
Significant adaptations

• Roots
• Anchor the plant and allows it to absorb water
  and nutrients from the soil
• Allows the shoot system to grow taller and
  further from water source

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
11
Significant adaptations

• Branching
• Megaphylls-leaves with a highly branched vascular
  system, typically larger
• Larger leaves means higher rate of photosynthesis
• Complex bodies with multiple sporangia which
  facilitated greater production of spores and
  increased survival despite herbivory

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
12
Life Cycle-Advantages

• Clustering and protective sporangia-protects
  spores
• Spores are light and easily dispersed by wind.
  Also water resistant which prevents the drying
  from the inside

• Dominating sporophyte generation
• The sporophyte doesnt have to develop
  independently
• Starts as embryo and is protected and nourished
  by gametophyte

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
13
Life Cycle-Limitations

• The need for water for fertilization
• Sperm are flagellated and swim to the eggs in the
  archegonium
• The need for free water, such as rainfall,
  greatly reduces the opportunities for successful
  fertilization
• Gametophyte is delicate
• Lacks protective tissue
• Has large vacuoles which means that it cannot
  recover from excessive dryness

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis
14
Importance

• Good for soil absorb arsenic, fix nitrogen
• Building block for many rainforests
• Horticulture eating and decoration
• Medicine vermifuge expelling helminthes

EBIO1240 - Lab 4 Katie Gates and Eddie Lewis