The lowest and thickest layer of the atmosphere is troposphere
        
                    
             
        
        
        
Answer:
The first bullet is theory 
The second bullet is Law
Explanation:
A scientific law is an explanation of a tested hypothesis and a mathematical method.
I am not totally sure but I believe this is correct 
 
        
                    
             
        
        
        
Answer:
chloroplast
Explanation:
it helps aid in the process of photosynthesis and the chlorophyll inside helps to pigment the plant and make it green
 
        
             
        
        
        
Answer:
a nucleus or organelles :)
Explanation:
a prokaryote is a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles.
 
        
             
        
        
        
Answer:
A. A pairs with U
Explanation:
In DNA, the nitrogenous bases are A, T, G, and C. In RNA, the nitrogenous bases are A, U, G, and C.
A pairs with U in RNA because it requires less energy to use uracil over thymine. 
Hope that helps.