SURVEY QUESTIONS 



What do we mean by the term behavior ? By what things or forces may 

 plants and animals be affected ? What are your sense organs ? What are 

 the parts of your nervous system ? What is an instinctive act ? What is 

 a habit ? How and why can man control things in his environment ? 



Wide World Photo 



UNIT XIV 



HOW HAS MAN BECOME THE CONQUEROR OF THE 



WORLD? 



Preview. We have seen many instances in which plants and 

 animals respond to stimuli. In our study of plants we found 

 examples of responses to light, gravity, and moisture. These 

 simple responses are called tropisms. But if we are asked to 

 explain why these responses took place, we can only say that 

 protoplasm exhibits the power of irritability by means of which 

 the organism is preserved from injuries and can obtain from its 

 environment the materials needed to carry on its life processes. 



The reactions of a dog to the sound of his master's voice or to 

 the odor of a piece of meat seem to be quite a different matter 



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