PROBLEM 4. How Plants Respond to Stimuli 



hi UNIT VI you ivill consider these problems: 



Problem i. How Are Our Bodies Protected against Microor- 

 ganisms? 



Problem 2. What Have Scientists Learned about Conquering 

 Some Common Diseases? 



Problem 3, (Optional) How Have Recent Discoveries 

 Changed Some of Our Ideas about Disease? 



Problem 4. How Do We Attempt to Stop the Spread of 

 Disease? 



Problem 5. How May We Achieve Better Health for All? 



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