classify anatomical difference between monocotyledonous stem and root

Asked by Gayathri manat | 18th Oct, 2014, 08:01: PM

Expert Answer:

Difference between monocotyledonous root and monocotyledonous stem:

Anatomical part

Monocotyledonous root

Monocotyledonous stem

Epidermis

  • Cells are thin walled, tightly placed and uncutinised.
  • Many epidermal cells protrude out in the form of unicellular root hairs. Thus this layer is also called piliferous layer.
  • Cells are parenchymatous, tightly placed and cutinised and devoid of chloroplast.
  • Epidermal layer bears stomata. This layer is without any appendages such as trichomes.

Cortex

  • Cells are parenchymatous, thin walled and enclose intercellular spaces. Cortical cells store food. The cells also conduct water from epidermis to inner tissues.
  • It is 2-3 layers thick and collenchymatous. It provides mechanical strength to the stem.

Endodermis

  • Single layered endodermis is present which consists of barrel shaped, closely packed cells without any intercellular spaces.
  • Endodermis is absent.

Pericycle

  • Pericycle is single layered and lies on the inner side of the endodermis.
  • Pericycle is absent.

Vascular Bundles

  • More than 6 vascular bundles are present.
  • Xylem and phloem bundles alternate each other.
  • Protoxylem lies in contact with the pericycle.
  • Metaxylem is present towards the centre of the root.
  • A parenchyamtous tissue lies between xylem and phloem called conjuctive tissue.
  • Conjuctive tissue does not form the vascular cambium.
  • Vascular bundles are large in number.
  • There are many vascular bundles scattered.
  • Each bundle is surrounded by the sclerenchymatous bundle sheath.
  • They are of conjoint and closed type.
  • The bundles are large towards the centre and small towards the periphery.
  • Phloem parenchyma is absent.
  • Cavities filled with water called schizolysigenous water canal or cavity.

Pith

  • The pith is well developed.
  • Cells are parenchymatous with intercellular spaces.
  • Pith cells store food.
  • Pith is absent.

Ground tissue

  • Lacks ground tissue.
  • Monocot stem does not show any distinction in general cortex, endodermis, pericycle and pith.
  • It is parenchymatous and occupies the entire stem from interior.

Answered by Sheetal Kolte | 20th Oct, 2014, 11:30: AM