Plant Evolution Evolved from green algae (450 mya) Multicellular Autotrophs Land Adaptations 1) Retain Moisture 2) Transport nutrients 3) Growing upright 4) Reproducing on land
Land Adaptations Problem: Retain Moisture Solution: Cuticle waxy coating prevents water loss cuticle
Land Adaptations Problem: Transporting Resources Solution: Vascular system tubes to transport nutrients Up from the roots; down from the leaves Allows taller growth glucose water
Land Adaptations Problem: Growing upright Solution: Lignin hardens cell wall gives wood strength mortar lignin
Land Adaptations Problem: Reproduction on land Solutions: Pollen: carried by wind/animals Seeds: hard coat protects embryo inside
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 Gametophyte (Haploid) Spores grow into a gametophyte Male gametophyte creates sperm Female gametophyte creates egg Sporophyte restarts when egg and sperm make zygote X X X X X
Kobe Kuiz • What traits do plants and plant-like protista 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? • What is the chromosome combination for the sporophyte stage? • What is the chromosome combination for the gametophyte stage? • What does the gametophyte stage create? • What does the sporophyte stage create?