Plant Evolution

1
Plant Evolution
2
Plant Evolution

• Evolved from green algae (450 mya)
• Both have same type of chlorophyll, store energy
  as starch, DNA similarities
• Green algae ancestor
• Multicellular body
• Cells w/ channels to communicate
• Reproduce w/ sperm egg
• Early plants
• Low growth (nonvascular)

3
Land Adaptations
cuticle

• Challenge Retain Moisture
• Early plants grew near waters edge
• Those that could survive longer dry periods were
  favored through natural selection
• Adaptations
• Cuticle waxy coating
• Stomata pores to allow gas exchange

4
Land Adaptations
glucose
water

• Challenge Transporting Resources
• Adaptation
• Vascular system tissue to transport nutrients
• Up from the roots (ex water)
• Down from the leaves (ex sugars)
• Allows for taller growth

5
Land Adaptations
Mortar
Lignin

• Challenge Growing upright
• Large plants need to support own weight
• Adaptation
• Lignin hardens cell wall gives wood strength

6
Land Adaptations

• Challenge Reproduction on land
• Adaptations
• Pollen carried by wind/animals
• Seeds hard coat protects embryo inside

7
Plant Ecology

• Mutualistic relationships
• Type of symbiosis where both organisms benefit
• Ex Plants (provides living space)/Bacteria
  (create nutrients)
• Ex Plants (provide food)/Animal (help pollinate)
• Herbivore interactions
• Defense adaptations
• Spines, thorns, chemicals

8
Review

1. What traits do plants and plant-like protista
   (algae) share?
2. Name 4 adaptations that plants have for life on
   land.
3. Which plant adaptation allows them to carry
   nutrients to great heights?
4. Which plant adaptation allows them to retain
   moisture?
5. What is the purpose of lignin?
6. Explain a symbiotic relationship between plants
   and other organisms?
7. How do plants protect themselves from predators?