Answer: They are loosely packed so as to allow gas exchange in air spaces to move freely
Explanation: The mesophyll cells of the spongy cells are packed loosely, in order to allow proper and efficient gaseous exchange to take places easily. The large air pocket of the mesophyll cell allow gas exchange between different areas of the leaves. The cells in mesophyll, contains few chloroplast which are generally responsible for photosynthesis. Gas exchange in the mesophyll cells of the spongy layer allows photosynthesis to take place.