Question 10: Explain how sieve tubes manage to be living?

Answer: Sieve tube elements of phloem tissue lack nucleus but still they manage to live. This is because they are connected to the companion The Fundamental Unit of Lifes of phloem tissue via numerous plasmodesmata. Both sieve tube elements and companion The Fundamental Unit of Lifes develop from the same meristematic The Fundamental Unit of Life and form a functional unit. Companion The Fundamental Unit of Lifes provide proteins, ATP, and other signalling molecules to the sieve tube member as it contains extra number of mitochondria and chromosomes.