Answer:
Polytene chromosomes may be defined as the giant chromosomes that contain alternate dark and light bands when view under the microscope. These chromosomes are found in the salivary gland of Drosophila.  
These glands are functionally highly active and contain thousand of DNA strands. These chromosomes are aligned parallel with each other as the replication is normal but the cells are unable to separate and fails to undergo the process of cytokinesis.
 
        
             
        
        
        
B: They represent different concepts.
 
        
                    
             
        
        
        
One hot dry summer is the ansrew
        
                    
             
        
        
        
The first one, is :
Embryology - The branch of biology and medicine concerned with the study of embryos and their development.
The second one is:
Vestial Traits - An anatomical feature or behavior that no longer seems to have a purpose in the current form of an organism of the given species.
 
        
             
        
        
        
The most important factor in creating diverse species is individual and separate environments. Species develop based on their unique environment, which "selects" for particular traits.