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 water’s 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 Challenge: Transporting Resources Adaptation:
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 Challenge: Growing upright
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 & Evolutionary Relationships
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 What traits do plants and plant-like protista (algae) share?
Name 4 adaptations that plants have for life on land.
Which plant adaptation allows them to carry nutrients to great heights?
Which plant adaptation allows them to retain moisture?
What is the purpose of lignin?
Explain a symbiotic relationship between plants and other organisms?
How do plants protect themselves from predators?