PHYSIOLOGICAL PROCESSES IN PLANTS 115 



Conclusions. 1. What generation does the prothallus represent ? 

 Explain. 



2. Show how there is alternation of generations. 



Observations. 1. Study Figure 33. Just where is the egg cell 

 located ? 



2. Just how must the antherozoid or sperm cell (0) reach the egg 

 cell (e) ? 



Conclusions. 1. Does the process of fertilization here take place 

 internally or externally ? Explain. 



2. Show if it is of any advantage to an egg cell that it be reached only 

 through a small tube. 



3. Could the egg cell be fertilized if the archegonial tube was perfectly 

 dry ? Explain. 



4. Fill in the following summary : 



Questions 



1. Explain the term ' alternation of generations.' 



2. What advantages result from alternation of generations ? 



3. Are ferns independent or dependent plants ? Explain. 



4. Which method of reproduction better enables a plant to fight 

 adverse conditions ? Which for rapid and easy multiplication ? 



5. What disadvantages to a moss plant that the sporophyte be de- 

 pendent on the leafy plant (gametophyte) ? What advantages ? 



6. What conditions favor the growth of molds ? 



7. What is meant by vegetative or asexual reproduction ? By sexual 

 reproduction ? 



8. What is a sporophyte ? Give an example. A gametophyte ? 

 Example ? 



0. What are parasitic plants ? Example ? Saprophytic ? Example ? 



10. What is the essential process of fertilization ? 



11. Why must male germ cells be so much more abundant than eggs ? 



12. Why must plants and animals reproduce themselves ? 



