Companion cells are closely associated with:
1. Sieve elements
2. Vessel elements
3. Trichomes
4. Guard cells
Transport of food material in higher plants takes place through:
1. Transfusion tissue
2. Tracheids
3. Sieve elements
4. Companion cells
A common structural feature of vessel elements and sieve tube elements is:
1. thick secondary walls
2. pores on lateral walls
3. presence of P-protein
4. enucleate condition