Answer:
The answer would be D
Explanation:
Carbohydrates supply energy with foods that have proteins, sugars and so on, they have polysachrides.
 
        
             
        
        
        
A I think but can you get a better picture of the questions
        
                    
             
        
        
        
Bacteriophages are viruses that infect and duplicate within a bacterium. Temperate phages (such as lambda phage) can keep reproducing using both the lytic and the lysogenic cycle.  
SO.... Bacteriophages  
I believe is the answer that you are looking .
Let me know if its right or wrong!!
 
        
             
        
        
        
The center portion of each intervertebral disc is a filled with a gel-like elastic substance. Together with the annulus fibrosis, the nucleus pulposus transmits stress and weight from vertebra to vertebra.
        
             
        
        
        
Answer:
A = Activator
B = Effector
Explanation:
An activator is a protein which typically binds to a short (50–1500 bp) region of DNA which might be located either upstream (mainly) or downstream of a gene so as to cause increased transcription. This particular region of DNA is known as enhancer and activator is also  known as transcription factor. Activator is a trans-acting factor which binds to the cis-acting factor which is enhancer so as to enhance transcriptional expression. 
But another protein named as effector may restrict activator from binding to the enhancer leading to a decrease in transcriptional expression by binding to the activator allosterically. Allosteric binding of effector to the activator causes conformational change in activator so it can no longer bind the enhancer.