Internet Encyclopedia of Science
BOTANY
A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

                   • HOME
• ABOUT
• CATEGORIES
• USE OF TEXT AND IMAGES
• NEWSLETTER

  



sieve-tube


sieve tube
A characteristic element of phloem, which functions in the transport of food materials, such as sugars and proteins, synthesized within a plant. A sieve-tube consists of elongated, thin-walled, living cells arranged in a longitudinal row and forming a connected series by means of perforations in their walls through which pass strands of cytoplasm. These perforations occur in groups known as sieve-plates in the end or lateral walls.

Sieve-tubes are remarkable in that their cells lack nuclei when mature. They are closely associated with parenchymatous companion cells with prominent nuclei.


Related category

   • BOTANY


Also on this site:

Encyclopedia of Alternative Energy & Sustainable Living
Encyclopedia of History


BACK TO TOP