BIO SCI 94 Lecture 11: Green Algae and Land Plants

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Robin Bush

Document Summary

The story of land plants is the story of adaptations that allowed photosynthetic organisms to move from aquatic to terrestrial environments. Once green plants made the transition to survive out of water, growth on land offered a ton of resources. Natural selection favored plants with adaptations that: prevented water loss, provided protection from uv radiation, moving water from tissues with direct access to water to tissues without direct access to water. The production of cuticle was the one innovation that made land transition possible. Cuticle are sheets of waxy substance and is a watertight sealant for aboveground parts of plants. The stoma consists of an opening called a pore , which is surrounded by guard cells. When guard cells lose water, they become limp and the stoma closes. When guard cells are turgid with water ,guard cells open the pore and allow co2 to diffuse in.