INTRODUCTION 



DEFINITIONS OF COMMON BIOLOGICAL TEEMS 



Biology is the science which discusses living things — ■ 

 plants, the lower animals, and man. These living things 

 move, breathe, feel, and get their food in varied ways. 



Man, for instance, does not move as a jellyfish moves, 

 nor does he breathe as a tree breathes. He has not the 

 same sensations as a frog, nor does he get his food as do 

 the flowers ; though lie and all other living things have 

 these functions 1 in common. Each living thing has its 

 parts especially adapted to its peculiar needs. Claws 

 serve a cat admirably for climbinor and for catching mice; 

 a frog has web feet to aid in swimming ; while hands are 

 better suited to the kind of things that a man has to do. 



Energy. — Everything that plants and animals do re- 

 quires energy. Without energy in some form they can- 

 not move or grow. Energy is produced in various ways. 

 In a steam engine fuel is consumed or oxidized to make 

 energy. In man the food taken into the body is con- 

 verted into energy by a slow kind of burning which we 

 call oxidation. 



Life Processes. — From the study of physiology we are 

 fairly familiar with foods, or nutrients, as they are some- 

 times called. Some of these are starch, sugar, fats, oils, 

 and mineral matter. The life of a plant or of an animal is 

 directly dependent upon its food. But food is not the 



1 Function has a scientific use in biology, where it is used to describe the 

 common living activities of animals and l > ' ant MMMMH7 f Bwn 



1 * C State Oik* 



