Which of the following is NOT a type of supporting tissue in plants?

Analyze the question: We need the option that is NOT a supporting (mechanical) tissue in plants.

Concept: Plants are supported by:

• Collenchyma: living cells with unevenly thickened (cellulose/pectin) walls. It supports young stems and petioles.
• Sclerenchyma: dead cells with walls thickened by lignin. It gives strong, rigid support (fibres and sclereids).
• Xylem: its lignified vessels and fibres give mechanical support to the plant, in addition to conducting water.
• Parenchyma: thin-walled living cells. They mainly store food and fill space, but when turgid they help support herbaceous plants.
• Cambium: a meristematic tissue. Its job is to divide and produce new cells (secondary growth), not to give support.

Working through the options:

• A. Cambium: a meristem for growth, so it is not a supporting tissue.
• B. Collenchyma: supporting tissue.
• C. Parenchyma: a basic/packing tissue. It can give some turgor support, but this is not its main role.
• D. Sclerenchyma: supporting tissue.
• E. Xylem: a conducting tissue that also supports.

Parenchyma could cause confusion here, since it is often classed as a simple permanent tissue, not strictly a "supporting" one. However, the best answer is still cambium, because it is a meristematic (dividing) tissue and not a permanent tissue.

Answer: A. Cambium

Exam tip: Remember "Cambium = Create new cells". Meristems (cambium, apical meristem) make new cells, while collenchyma and sclerenchyma are the classic mechanical tissues. When a question asks for the odd one out, ask which tissue has a growth role and not a structural one.