Question

Which of the following does not contain pith?

• A. Siphonostele
• B. Protostele
• C. Eustele
• D. None of the above

Answer 1

The correct option is B Protostele

Protostele is the most primitive type of stele with central xylem surrounded by phloem and pericycle. Pith is absent from them. Medullation (appearance of pith) of a protostele with central pith is called as siphonostele and thus has central pith surrounded by xylem, phloem, and pericycle. Separation of vascular strands by parenchyma in siphonostele gives rise to eustele.

Thus, the correct answer is B.