Perennial Shrubs I know it is late.
        
             
        
        
        
Answer:
the branch of biology and medicine concerned with the study of embryos and their development.
Explanation:
sorry if it is wrong!!!
 
        
             
        
        
        
Answer:
<h2>c. Division of these two groups occurred after the protostome developmental sequence appeared. </h2>
Explanation:
- Protosomes are such types of organisms in which the mouth part developed first during embryonic development.
-  Those animals in which anus develop first are known as deuterostomes.
-   This differentiation takes place during the embryonic development of the organisms.
-  Since lophotrochozoan and Ecdysozoa both are protostomes animals and categorized on the basis of molecular evidence.
-  Thus these two groups were formed after the appearance of the protostomes.