Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I know that sieve tubes do not have ribosomes, nuclei and cytoskeletal elements. What other organelles does it not have? Does it have a cytoplasm?

share|improve this question
A cell without a cytoplasm is not a cell. – Amory Sep 30 '13 at 18:46

The sieve tubes of the phloem in angiosperms consist of sieve tube elements or members. These are cells which lose their nucleus, ribosomes, and vacuoles at maturity. They of course have cytoplasm, and it is connected by channels to companion cells (which do have these organelles). The sieve tube elements retain mitochondria and plastids. See the Wikipedia page and this page for more details.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.