question_answer 48)

  Which of the following does not lose their nucleus at maturity? (a) Companion cells        (b) Red blood cells           (c) Vessel                            (d) Sieve tube cells

Answer:

  (a) Companion cells are present along the sieve tube are connected to them via plasmodesmata. These cells are metabolically active and sieve tube elements are dependent on these cells they do not lose nucleus at maturity. RBC vessels and sieve tube cells lose their nucleus at maturity.