Answer:
The given blank can be filled with operator. 
Explanation:
The proteins that assist in turning on or turning off the function of a specific gene by getting combined with certain sections of the DNA are known as transcription factors. The transcription factors that activate the transcription of a specific gene are known as activators, while that prevents transcription and is termed as repressors.  
A repressor can be an RNA or a DNA binding protein, which prevents the articulation of genes by getting combined with the operator. A repressor, which binds with DNA prevents RNA polymerase from getting combined with the promoter, which further inhibits the transcription of the genes into mRNA.  
 
        
             
        
        
        
Answer:
What are some differences between a food chain, web, or energy pyramid? Food chains show a limited feeding relationship between only a few organisms. Energy pyramid is the visual representation of the amount of energy, population, or biomass at each trophic level.
 
        
                    
             
        
        
        
When a stimulus is produced it signifies the production of sensation in the sensory organs. This sensation through the sensory organs (eyes, ears, nose, skin and tongue) is sent to the sensory nerve connected to these sense organs. These sensory nerves send nerve impulses through the nerve fiber to the spinal cord. From the spinal cord the nerve impulse is transferred to motor nerves.
The motor nerve then sends response to the stimulus though the same path to the region from which stimulus was received and thus the body responds through muscular activity. Such as removal of heat from the heated object if heated sensations were received.
 
        
             
        
        
        
Answer:
A.  a cell process that releases energy from food 
Explanation: