Question

Removal of ring wood of tissue outside the vascular cambium from the tree trunk kills it because

• A. Water cannot move up
• B. Food does not travel down and root become starved
• C. Shoot become starved
• D. Annual ring are not produced

Answer 1

Answer: (B)

Food does not travel down and root become starved

In angiosperms xylem tracheids and vessels transport water and minerals, whereas phloem tissue transports sugars. In woody dicot stems showing secondary growth, the secondary phloem is present in a ring outside the vascular cambium. The primary phloem is crushed by the activity of vascular cambium and hence is not considered. The secondary xylem is present inside the vascular cambium. If a ring of tissue outside vascular cambium is cut then secondary phloem is removed, sugars cannot travel from aerial photosynthesizing parts of plants to roots, which are non photosynthetic. Consequently roots are killed and the plant dies.