Question

Sieve tubes differ from sieve cells in

• A. Being shorter
• B. Being dead
• C. Lacking nuclei
• D. Having sieve pores at end walls

Answer 1

The correct option is D Having sieve pores at end walls

Phloem is a heterogeneous tissue made up of phloem parenchyma, fibres, sieve tubes and companion cells. Sieve tube elements are also called as sieve tube members. At the interface between two sieve tube members in angiosperms are sieve plates, pores in the plant cell walls that facilitate transport of materials between them. These are called as 'sieve pores'.

Sieve cells are long, slender, conducting cells of the phloem that do not form a constituent element of a sieve tube, but which are provided with relatively unspecialized sieve areas.

So, the correct answer is option D.