33 



34 



vi CONTENTS 



CHAPTER PAGE 



Membrane Permeability 32 

 Diffusion 

 Osmotic Pressure 



Function of the Cytoplasm 36 



Function of the Nucleus 38 



Function of the Centrosome 38 



Plastids 38 



Plants and Animals 39 



Metabolism 40 



Photosynthesis 41 



Plant Nutrition and Animal Nutrition 42 



The Nitrogen Cycle 44 



The Carbon Cycle 45 



One Cell and Many Cell Organisms 46 



Tissues 47 



Organs 47 



Cooperation 50 



Suggested Readings ^ 50 



III. The Biology of Unicellular Forms and their Relation 



TO THE Biology of Multicellular Animals 52 



Fields of Study 52 



Types of Protozoa 54 



Amceba 55 



Nutrition 57 



Respiration 58 



Excretion 60 



Amoeboid Movement 61 



Irritability in Amoeba 63 



Reproduction in Amoeba 63 



Paramoecium 64 



Nutrition in Paramoecium 66 



Irritability in Paramoecium 67 



Reproduction in Paramoecium 69 



Conjugation Jo 



Metabolism 7^ 



Symbiosis 7^ 



Parasitism 73 



Malarial Parasite 74 



Enzymes 76 



Catalysis 78 



Anaerobes 81 



