Molecules of mRNA are composed of relatively short, single strands of molecules made up of adenine, cytosine, guanine and uracil bases held together by a sugar phosphate backbone.
 
Hope This Helps, Lexi
 
        
             
        
        
        
Answer:
Phytoplankton use carbon dioxide and produce oxygen during photosynthesis; phytoplankton, fish, and seals use oxygen and produce carbon dioxide during respiration. Which can provide the most energy in an ecosystem
Explanation:
 
        
             
        
        
        
I think the correct answer is necrotic tissue. Debridement is the removal of unhealthy tissue from a wound or skin to promote healing. It can be done using surgical methods, chemical, mechanical or autolytic (own body process)removal of the tissue. The unhealthy tissue may be a damaged, dead or infected tissue that is removed to improve the potential of healing of the remaining healthy tissue.
        
             
        
        
        
Think it’s answer D but it maybe B 
hope this helps!!
sorry if it’s wrong