Write the function of

a. Sieve tube – They help in translocation of synthesized food throughout the plant. It is present in phloem tissue.

b. Interfascicular cambium – It facilitates secondary growth in dicot stem and root and also helps in the formation of the vascular cambium.

c. Collenchyma – It provides mechanical support to young stem. Its cells have angular thickening at corners.

d. Aerenchyma – It provides buoyancy to floating plants.