Water! It is essential to have water
        
                    
             
        
        
        
Answer:
CHLOROPLAST
Explanation:
As stated in this question, plant cells are capable of producing their own food in form of sugar (glucose) using energy from sunlight in a process called PHOTOSYNTHESIS. Photosynthesis is the process by which green plants and other certain organisms synthesize their own food using light energy. 
The ability to carry out this photosynthetic function is embedded in a structure found in plant cells called CHLOROPLAST. Chloroplast contains a pigment called CHLOROPHYLL, which captures light energy from the sun. Generally, the the function of producing sugar in the presence of sunlight (photosynthesis) occurs in the CHLOROPLAST. 
 
        
             
        
        
        
Explanation:
One of a number of alternative forms of the same gene occupying a given position, or locus, on a chromosome is allele. 
 
        
                    
             
        
        
        
Answer:
Given that a negatively charged rod is brought closer to two metal spheres which are in contact with each other as shown: So, free electrons from rod will be attracted towards the metal spheres.
 
        
             
        
        
        
The primary source of stem thickening in plants is the vascular cambium. It is a plant tissue located between the phloem and the xylem and in the root of a vascular plant. It is the source of secondary growth or the radial growth of the stem of a plant.