Light that appears white or nearly white to humans is made up of spectrum of visible light i.e. combination of violet, indigo, blue, green, yellow, orange and red.
        
             
        
        
        
48.73g to kg =48.73*1000
                   =0.04873kg
total mass=0.0473kg*25
               =1.21825kg
(idk about the significant figures, SORRY)
        
             
        
        
        
We are dependent on photosynthesis because photosynthesis is an essential process in our natural environment that helps to sustain plant life, produce oxygen, reduce Co2, and promotes human and animal well-being. 
        
                    
             
        
        
        
What are you asking for here? we need a solid question not a statement.
i'd say that the statement is true. we cant define life because we do not know what life, in essence, is. we can define, however, the characteristice of all living things:
Movement
Respiration
Sensitivity
Nutrition
Excretion
Reproduction
Growth
MRS NERG