VITAL ANIMAL LIFE PROCESSES 73 



3. List the variety of methods used for respiration in animals. 



4. How does cellular respiration differ from external respiration? 



5. Give the chemical equation for the oxidation of glucose within the cell. 



6. Sometimes persons with kidney trouble are put on a low protein diet. What 

 would be the reason for this? 



7. Tell how radioactive isotopes may be used to study the relation between 

 cell metabolism and excretion. 



8. Some of the small, simple animals have no excretory organs, yet larger 

 animals cannot exist without these organs. Explain. 



9. Distinguish between sexual and asexual reproduction. 



10. Explain the relationship between cells, tissues, organs, and organ systems. 



11. List the organ systems which are present in the higher forms of animal life. 



