D. Proteins are composed of amino acids and determines all the structures and functions of the organism.
        
                    
             
        
        
        
Answer:a. A cataract is a clouding of the lens. Some cataracts are congenital, but most are due to age-related hardening and thickening of the lens, diabetes mellitus, or exposure to UV rays over time. The lens can be removed and replaced 
with an artificial lens.
Explanation:
 
        
             
        
        
        
The correct answer is D. Tortoises and snails have analogous organs, and they don't belong to the same species.