1. Plant Evolution

2. Plant Evolution Evolved from green algae (450 mya)
Both have 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 Challenge: Retain Moisture
cuticle
Challenge: Retain Moisture
Early plants grew near waters edge
Solutions
Cuticle: waxy coating
Stomata: pores to allow gas exchange

4. Land Adaptations Challenge: Transporting Resources
glucose
water
Challenge: Transporting Resources
Solution: Vascular system: tissue to transport nutrients
Up from the roots (ex: water)
Down from the leaves (ex: sugars)
Allows taller growth

5. Land Adaptations Challenge: Growing upright
mortar
lignin
Challenge: Growing upright
Large plants need to support own weight
Solution
Lignin: hardens cell wall; gives wood strength

6. Land Adaptations Challenge: Reproduction on land Solutions
Pollen: carried by wind/animals
Seeds: hard coat protects embryo inside

7. Alternation of Generations
Plants alternate between a diploid organism and a haploid organism
Sporophyte (diploid)
Zygote created
Zygote grows into adult sporophyte
Sporophyte makes spores by meiosis
Gametophyte (Haploid)
Spore grows into a gametophyte
Male gametophyte creates sperm
Female gametophyte creates egg
Sporophyte restarts when egg and sperm make zygote X X X X X

8. Plant Ecology Mutualistic relationships Herbivore interactions
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

9. 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?