BIO 2135 Chapter 0: Lab 1 Prep
Document Summary
Single celled organisms require less energy than cold-blooded animals. Large animals rely on large surface areas to meet the high requirements. Therefore need adaptations as they get bigger or else it wouldn"t be efficient. Spherical shape = lowest surface to volume ratio. Changing body shape is an adaptation to increase surface area:v ratio in smaller animals. Larger animals use morphological, physiological or behavioral adaptations to enhance diffusion rates. Diffusion affected by: surface area, permeability inversely proportional to thickness, difference in the concentration between 2 sides of membrane. To max oxygen diffusion & minimize water loss you use adaptations relating to these factors. no respiratory system = change in body shape small animals become spherical/cylindrical large animals become flattened terrestrial animals have outer body impermeable to water. Mixing at exchange surfaces is used to increase diffusion. For each organism: estimate external surface area, estimate volume, estimate sa:v ratio. Tetrahymena is more circular and short with hairlike projections.
