Seed Plants

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Seed Plants
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Classification - Seeds

• Seedless Plants
• Mosses ferns (ferns are vascular plants) make
  spores, not seeds
• Embryo from sexual reproduction develops within
  archegonium in parent plant
• Embryo does not need to await favorable
  conditions to develop

• Seed Plants
• Embryo from sexual reproduction develops in seed
• Seeds dispersed, await favorable conditions to
  germinate
• Seeds formed in cone (gymnosperm) or fruit
  (angiosperm)

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Classification - Flowers

• Naked Seed Plants Gymnosperms/Coniferophyta
• Seeds in cone
• No flowers
• Male female cones make gametes (egg sperm)
• Conifers pines, firs, spruces, cypresses,
  redwoods

• Flowering PlantsAngiosperms/Anthophyta
• Seeds enclosed in a fruit
• Flowers make gametes (eggs sperm)
• Fertilized flower ? fruit

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Sexual Reproduction in Seed Plants (ch. 30)Life
Cycle of Coniferophyta/Gymnosperms
Male gametophyte
(n)
No more spores
(n)
In pollen cone and ovule of female cone Meiosis
to produce gametophytes (n)Mitosis to produce
gametes (n)
Pollination Water not needed
Female gametophyte
(2n)
(2n)
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Life Cycle of Anthophyta/Angiosperms
In anther and ovule Meiosis to produce
gametophytes (n)Mitosis to produce gametes (n)
Male gametophyte
Pollination Water not needed
Fertilization
Female gametophyte
No more spores
Mitosis
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Your Textbook picture
Double fertilization 2 sperm cell egg polar
nuclei ? Zygote (2n) Endosperm (3n)
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Seed Germination

• Germination embryo in seed starts to grow
  (usually triggered by water absorption)
• Radicle first shoot/part of embryo to appear
  outside seed develops into root
• Cotyledons seed leaves, not real leaves, do
  not photosynthesize
• Monocot ? one coteledongrains rice, corn,
  wheat, etc.
• Dicot ? two coteledonslegumes beans, peas, etc.

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If April showers bring May flowers,what do May
flowers bring?Pilgrims.
Botanists have developed a vegetable that
eliminates the need to brush your teeth.Bristle
sprouts.  
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Seed Structure Development in Flowering Plants
Double fertilization ? seeds containing embryo
and endosperm(one sperm for egg, one for
endosperm) Endosperm contains
starch/oil/protein -- energy for developing embryo
Each ovule develops into a seed. The micropile
is the small opening where sperm came into ovule
for fertilization.
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Seed Development
Hypocotyl embryo shoot under cotyledons ?
develops into first stem
Epicotyl embryo shoot above cotyledons ?
develops into first leaves
Cotyledons (seed leaves) eventually fall off
Brassica, our lab plant
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Bean Seed
Hilum Scar where ovule attached to ovary
Micropile Scar where pollen tube entered ovule
Radicle emerges here,becomes root
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Development of Bean Plant
cotyledons
epicotyl
hypocotyl
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Corn Kernel / Seed / Fruit
Silk Scar (pollen tube entered ovule here)
Embryo
Point of attachment
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Flowers

• Sexual reproductive structures (contain
  gametophytes)
• Attract pollinators
• Make gametes by mitosis
• Anther makes pollen containing sperm
• Ovary makes ovules ? eggs
• Seeds/fruits develop from flower ovary
• Pollination stigma receives pollen, pollen tube
  forms
• Double fertilization in ovary
• 2 sperm cells egg --gt embryo endosperm
  (endosperm food for embryo)

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Flower Structure(use to label the diagram in
your notes)
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Flower Structure
Perfect/complete Flowers have both male female
parts Imperfect Flowers have either male or
female parts
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Formation of Female Gametophyte -- Terms you need
to know/ID Ovary, ovule, female gametophyte,
meiosis, egg polar nuclei, endosperm, double
fertilization
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Formation of Male Gametophyte -- Terms you need
to know/ID Anther, male gametophyte (pollen),
meiosis, sperm (2, for double fertilization)
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Fruits

• Fleshy Fruits
• High moisture content
• Apples, cherries, grapes, strawberries, tomatoes,
  cucumbers, etc.

• Dry Fruits
• Low moisture
• Walnuts, acorns, wheat kernels, dandelion
  parachutes

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Fleshy Fruits
Berry
Pome
Drupe
Aggregate
http//www.csdl.tamu.edu/FLORA/201Manhart/repro/fl
eshyfruits/fleshyfruits.html
Multiple
Accessory
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Dry Fruits
Policidal capsule
Nut
Silique
Follicle
http//www.csdl.tamu.edu/FLORA/201Manhart/repro/dr
yfruits/dryfruits.html
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Dry Fruits
Samara
Legume
Winged schizocarp
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Asexual Reproduction in Plants

• Vegetative reproduction occurs naturally, very
  fast, via modified ground surface/underground
  stems that make buds
• Stolons/runners close to ground surface ex.
  aspen groves (clones), water hyacinths
• Rhizomes underground ex. bamboo plants
• Tubers swollen tips of rhizomes modified for
  food storageex potatoes
• Corms and bulbs modified for food storage ex.
  tulips, onions
• Artificial propagation people do it cutting,
  grafting, tissue culture
• faster than seeds, produces genetically identical
  crop plant regenerates parts
• Ex bananas, apples, grapefruits, grapes,
  potatoes, pears are often grown by artificial
  propagation