chloroplast contains chlorphyll . Chlorophyll is used in photosynthesis to produce glucose . (photosynthesis is a process where green plants manufacture simple sugar (glucose) from carbondioxide and water by using sunlight ) 6co2+6h2o=c6h12o6+6o2
if theres no chloroplast no glucose will be produced so animals will have no energy. chloroplast must be present in order of photosynthesis to take place and produce glucose , when plants produce glucose animals get the energy needed by feeding on plants (in simple words animals eat the sugar that plants have produced )