I would say the answer is B.) There is data at this digit's location, although I have to admit I am not completely sure, nor really educated in this area. Sorry I couldn't be of more help. :)
        
             
        
        
        
Answer is B. The number of the question that should be considered next. Let's say your organism has a dorsal fin, then you would go to 5. Then you choose a or b depending on the location of the tail. Let's choose 5a for now. Across from it says 6, so you go to 6
        
                    
             
        
        
        
A protein that is part of the synaptonemal complex (SC)
        
             
        
        
        
Answer: what is Acetyl CoA is made from pyruvate under aerobic conditions in the mitochondria. The process of conversion is irreversible. I don't know the other half I'm sorry. 
Explanation:
 Acetyl CoA Used by the citric acid cycle as a fuel. Carbon acetyl groups are converted to CO2 and ATP and electrons (carried by NADH and FADH2) create even MORE electrons.  Acetyl CoA is made from pyruvate under aerobic conditions in the mitochondria. The Process of conversion is irreversible. 
 
        
             
        
        
        
Answer:
A.
Explanation:
Because the trait undergoes a secondary loss; it has been there but it doesn't always appear in all generations.