Vascular Plants

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Vascular Plants
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Moving to Land

• Overtime, 500 millions of years ago, plants on
  Earth evolved from aquatic to terrestrial
  environments
• What are some problems to overcome?
• Material transport
• Structure/support
• Desiccation
• Gas exchange

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Benefits to moving to land

• easier access to sunlight for photosynthesis,
• continuous free movement of carbon dioxide and
  oxygen

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Vascular Plant Organs
Roots, stems and leaves
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Vascular Plant Organs

• Roots Absorb water and dissolved
  nutrients from soil
• Anchor plants in the soil and
  prevent them from being knocked down by
  wind
• Storage site for food storage

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Vascular Plant Organs

• Stems Support - hold leaves up towards the
  sun for optimal exposure for
  photosynthesis
• Transport between roots and
  leaves (via vascular tissue, phloem and
  xylem
• Storage site for food storage

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Vascular Plant Organ

• Leaves Photosynthesis and Cellular respiration
• Formulas????
• Modified to reduce transpiration
• Cuticle and pores

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Vascular Tissues

• http//www.harcourtschool.com/activity/vascular/va
  scular.html

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Vascular Plant Tissues

• XYLEM Carries water and dissolved nutrients from
  the soil, from the roots, into the stem and into
  the leaves.
• It forms a continuous set of tubes that stretch
  from the roots to the leaves

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Vascular Plant Tissue

• PHLOEM Distributes food made in the leaves
  throughout the plant.
• The glucose produced by photosynthesis in the
  leaves, moves down towards the roots.

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Questions

• The direction of glucose transport can be
  reversed in situations when the glucose levels in
  the roots are greater than in the leaves.
• In which situations might this occur?

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Vascular Tissues
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Vascular Plants

• 10 phyla
• Includes1) seedless vascular plants (ie. ferns)
• 2) plants with unprotected
  seeds
• (ie. Cone-bearing plants) 3) flowering
  plants

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Similarities with mosses

• 1) free-living gametophyte
• 2) no seeds
• 3) mobile sperm that require water for
  fertilization

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Differences from mosses

• 1) a vascular system which transports water,
  nutrients and photosynthetic products around the
  plant,
• 2) sporophytes as the dominant life stage
• 3) stomata

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Fern

• Most diverse group of plants
• Most abundant after flowering plants
• Alternation of generation between gametophyte
  (haploid) and sporophyte (diploid)

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Fern Life Cycle

• http//trc.ucdavis.edu/biosci10v/bis10v/media/ch15
  /fern_life_cycle_v2.html
• Takes notes from fig 10.7

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Fern Life Cycle

• -gametophyte (n) makes gametes sperm (n) and
  egg (n)
• -gametes fuse when mature, fertilization
• -zygote (2n) develops attached to gametophyte
  (n)
• -zygote becomes spore-bearing sporophytes (2n)
• -spores (n) disperse and develop into
  gametophytes(n)
  

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Fern Sporophyte
-large leaves are called fronds -fronds
contain spores on the underside, contained in a
sac called sporangia -sporangia cluster together
to form a sori
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Fern Gametophyte
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Young sporophyte growing out of a gametophyte
Sori containing clusters of sporangia
Grape-looking structures are individual sporangium
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Video of sporagnium releasing spores