540 



THE DEVELOPMENT OF THE INDIVIDUAL 



8. Tell how the three types of muscles originate. 



9. Tell how membrane and cartilage bones originate. 



10. Describe the formation of the three kinds of kidneys. 



11. Discuss the abnormalities that bring about mixed sex characteristics. 



12. The sex of human embryos cannot be determined until after they are about 

 two months of age. Why is this? 



13. Describe the origin and function of the four embryonic membranes of the 

 land vertebrates. 



14. How does the early embryonic development of a mammal differ from that 

 of Amphioxus ; the frog ? 



15. Discuss the importance of the organizer in the development of embryos. 



16. What is the role of the genes in relation to organizers in the development 

 of the embryo? 



