Which of the following is an incorrect statement?
Answer: (C) Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles. Answer: (c) Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles.
- A.The perinuclear space forms a barrier between the materials present inside the nucleus and that of the cytoplasm
- B.Nuclear pores act as passages for proteins and RNA molecules in both directions between nucleus and cytoplasm
- C.Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles✓
- D.Microbodies are present both in plant and animal cells
Correct Answer
(C) Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles
Solution & Explanation
Answer: (c) Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles. Solution: This is the incorrect statement. In phloem, the mature sieve tube element is an enucleate living cell – at maturity it LOSES its nucleus and most cytoplasmic organelles, and its functions are controlled by the adjacent companion cell. The other three statements are correct: the perinuclear space separates nucleoplasm from cytoplasm, nuclear pores allow two-way movement of proteins and RNA, and microbodies occur in both plant and animal cells. NCERT Reference: NCERT (Class XI, Anatomy of Flowering Plants – The Tissues / complex permanent tissue – phloem subsection, pre-2023 rationalisation text): mature sieve tube elements lack a nucleus at maturity and are associated with companion cells that control their function.