BIO-8 Lecture Notes - Lecture 31: Nitrogen Cycle, Nitrogen Balance, Osmoregulation
Document Summary
Shallow roots take up water after rainfall. Able to rapidly uptake water from brief rain events in which the rain does not penetrate very far into the soil long roots can access deeper water. Have roots that can extend several meters down into the soil, allowing the shrubs to access water that is very deep below the surface. Resins and waxy cuticles protect plants from direct sunlight and slow water loss. Boundary layer of still air traps moisture/reduces evaporation. Small leaves with high vein density prevent damage via embolisms (air bubbles in veins) which are common in water-stressed environments. Terrestrial environments pose a challenge for animals to balance water, salt, and nitrogen. Homeostasis - an organism"s ability to maintain constant internal conditions in the face of a varying external environment. Water and salt balance (osmoregulation) in animals - animals acquire minerals in water and food consumed; water intake and urine excretion eliminate excess salts.
