Question

Which of the following is enucleate at maturity?

• A. Companion cell
• B. Meristemic cell
• C. Parenchyma cell
• D. Sieve tube cell

Answer 1

The correct option is D Sieve tube cell

Phloem is composed of - sieve tube elements, companion cells, phloem parenchyma and phloem fibres.

• Sieve tube elements are long, tube-like structures and are associated with companion cells. Their end walls are perforated to form the sieve plates. A mature sieve element possesses pheripheral cytoplasm and a large vacuole but lacks a nucleus. It becomes enucleate due to the degeneration of its nucleus during its developmental process.

The companion, parenchyma and meristematic cells possesses the nucleus throughout its life.