Plants
What is a plant? A multicellular eukaryote with cells surrounded by cell walls made of cellulose and with a waxy waterproof coating called a cuticle.
Problems Faced by Living on Land 1. Dehydration 2. Exchange of Gasses 3. Transport of Nutrients 4. Support for Growth
Water Loss ….Cuticle and Guard Cells Gas Exchange ….Stomata Material Transport ….Xylem and Phloem
Plant Phylogeny Green algae about 400 million years ago. Both have cell walls made of cellulose.
Both have same photosynthetic pigments. Both store energy in the form of starch. Both exhibit alternation of generations.
Plant Reproduction
Advantages of Seeds: Protection: Drying out, damage, disease Nourishment: Food for the start Plant dispersal: Wind, Water, Animals Delayed Growth: Droughts, winters
Roots Anchor the plant in the ground Absorb water and minerals form the soil
Leaves Photosynthesis in the Mesophyll and gas exchange.
Tropisms