Dear student,
The formation, structure, and functioning of the different living beings are different which are controlled by the genetic material. The plants cannot move around like animals to get their food, they obtain their food from the sunlight using chloroplast and carbon dioxide. Therefore, their genetic material has the information for the formation of chloroplast to obtain their food while it is not found in others because they do not have the information in their genetic material to form the chloroplast. Hence, the chloroplast is found in only plants.
Regards