T h e P l a n t s

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T h e P l a n t s
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Plants

• Eukaryotic
• Most plants contains photosynthetic pigments
  (e.g. chlorophyll) for photosynthesis
• Autotrophic
• Can be divided into two groups
• Non-flowering plants
• Flowering plants

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Non-flowering plants

• 4 groups
• Algae
• Mosses
• Ferns
• Gymnosperms

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Algae

• Aquatic
• Simple multicellular plants
• No root, stem or leaf
• Contain photosynthetic pigments (e.g.
  chlorophyll) for photosynthesis

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Benefits / harms of algae

• As primary producer
• Oil producer
• Oxygen producer
• Used in sewage / water treatment plant
• Used in commercial processes
• Algal bloom
• Toxins to kill fishes
• Affect water supply

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Mosses

• With simple leaves and stems
• No root
• with rhizoids for anchorage and absorption of
  water
• No vascular tissues
• Reproduce by spores
• Found in damp area

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Bryophytes
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Mosses (Division Bryophyta)

• Each plant grips the substratum with rhizoids
• Photosynthesis occurs in the upper parts of
  plants
• Cover about 3 of land surface and contain vast
  amounts of organic carbon

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The gametophyte adaptation evolved in bryophytes

• The gametophyte condition was a pivotal
  adaptation -
• Antheridium (male gametangium) produces
  flagellated sperm cells
• Archegonium (female gametangium) produces egg -
  fertilisation/embryo development occur within
  female organ
• Bryophytes are not totally independent of aquatic
  habitat
• Need water for sperm to swim in
• Have no vascular tissue - diffusion

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Moss showing reproductive structures
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Alternation of generations
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Ferns

• With true roots, stems, leaves and vascular
  tissues
• Reproduce by spores
• Live in damp places

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A sporophyte-dominant life cycle evolved in
seedless vascular plants
MITOSIS
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Gymnosperms

• Reproduction by producing seeds
• Seeds develop in cones, not enclosed by fruits
• ? naked seeds
• Needle-shaped leaves to reduce water loss

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Male or Pollen Cones
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Female or Seed Cone
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Angiosperms (Flowering plants)

• With flowers for reproduction
• Seeds are produced inside the fruit (matured
  ovary)

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Two groups of flowering plants
Monocotyledons
Dicotyledons
Cotyledons
Two
One
Leaf venation
Netted
Parallel
Root system
Tap root system
Fibrous root system
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D i c o t s
Primary root - system
net-veined leaves
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M o n o c o t s
Parallel - veined leaves
Adventitious root - system
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H.W. p. 210 Q.1copy the question
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E n d P l a n t s