which of the following elements is essential for photosynthesis as well as helps to maintain the structure of protein factory of the cell? (1) Mg (2) N (3) Fe (4) Ca

@ vansh 
option no 1 will turns out to be the correct option . 
one atom of magnesium is present at the center of combination of eight nitrogen containing carbon rings . 
its also the only element which is present at the center of chlorophyll molecule , 
HOPE IT CLEARS 

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