BIOL 111 Lecture Notes - Lecture 5: Stoma, Bract, Meiosis

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: All

Document Summary

To reproduce: protection of gametes from dehydration and successful fertilization. Maintain physical structure and posture of the body. Obtain sufficient water and nutrients from surrounding. Maximum body size from optimal nutrition and growth conditions. No special protection of gametes needed can be released into water and there are a lot. No problem to maintain physical structure and posture because water provides buoyancy don"t have to support their weight. Water and minerals enter the body by diffusion no special organs/structures needed. Photosynthesis is limited by attenuation of light intensity under water. Limited body size because photosynthesis is not maximized. Water conservation through controlled loss through regulated openings = stomata (water loss needs to be controlled) Special pathways for distribution on water, minerals and photosynthetic products = xylem and phloem tissues. Female gametes kept anchored inside a protective structure. Sperm may be motile/immotile but carefully released in the vicinity of the egg. Evolution of seed habit resistant to dehydration.