<span>Bio-indicators are macro-invertebrates that detect Water Quality based on how tolerant they are to pollution. The number of species of each type of Bio-indicator (pollution tolerant, intolerant, and semi-tolerant) will calculate the index of the water.</span>
        
             
        
        
        
Answer:
Enzymes can only be used once
Explanation:
Enzymes are there forever 
 
        
             
        
        
        
Answer: (A) a membrane‑bound organelle with stacks of thylakoid discs called grana. 
(E) the main site of photosynthesis in a plant cell. 
Explanation:
The plant chloroplast is a large organelle, it is bounded by a double membrane like structure that is chloroplast envelop.
The chloroplast consists of chlorophyll pigment which traps the light energy from sun and converts it into chemical energy in the form of ATP. Thus the chloroplast is the main site for photosynthesis. Including the inner and outer membrane structure it also posses the third internal membrane structure which is called as the thylakoid membrane. The thylakoid membrane forms the network of flat discs which are called as thylakoids, the thylakoids are arranged in stacks which are called as grana. 
The thylakoid membrane is the center point for the synthesis of ATP through a chemiosmotic process.