BIOL108 Lecture Notes - Lecture 12: Charophyta, Phragmoplast, Sporopollenin

• School: University of Alberta
• Department: Biology (Biological Sciences)
• Course: BIOL108
• Professor: Lien Luong

Document Summary

The move to life on land (~500 mya) More atmospheric co2 rich source of mineral nutrients fewer herbivores & pathogens = less competition or danger for plants less water. How did early ancestors of plants overcome these challenges? through adaptations & reproduction on land. Charophytes and land plants share a common ancestor: Common traits: rings of proteins in plasma membrane. Are linear in non- charophycean algae: similar structures of the sperm. But only for those with flagellated sperm: phragmoplast (microtubules) during cell division they construct a cell plate between incipient cells that becomes a new cell wall. Adaptations to life on land: sporopollenin - tough polymer (keeps them from drying out) Keeps them from drying out and makes them resistant to physical stresses. Organisms with this trait would have survived better, contributing more to the genetic makeup of the next generation = natural selection. Synapomorphies of land plants (characteristics unique to plants; not in charophytes: adaptation for water conservation.