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You are given a fairly old piece of dicot stem and a dicot root. Which of the following anatomical structures will you use to distinguish between the two?

  • Option 1)

    Secondary xylem

  • Option 2)

    Secondary phloem

  • Option 3)

    Protoxylem

  • Option 4)

    Cortical cells

 

Answers (1)

best_answer

As we discussed in

Anatomy of Dicot Stems -

  • In contains outer single layer called epidermis, convered by cuticle, bears trichomes (multicellular hairs). Epidermis lacks chloroplast.
  • Cortex is divided into hypodermis, general cortex & endodermis.
  • Pericycle is situated in between endodermis & vascular bundles.
  • Vascular bundles (wedge shaped) are arranged in a ring. It is conjoint, collateral and open. Eustele is present.
  • Pith is made up of paranchyma cells. Function of pith is storage of water and food.
  • Pith ray or medullary ray is present built in pith which radially conduct food and water.

 

- wherein

Anatomy

 

 

Internal Structure (Anatomy) of Dicot Roots -

  • Epiblema single layer, cuticle and stomata are absent, unicellular roots hairs are present.
  • Epiblema is also known  as rhizodermis or piliferous layer. Root hairs are present in maturation zone of root, cells of epiblema which develop roots hair called trichoblast.
    No. of root hairs in cortex is made up of parenchymatous cell.
  • Chloroplast is absent but present in plant cell and trapa so they are photosynthetic.
  • Endodermis is present between cortex and pericycle casparian strips are present on vodial and tangential wall of endodermis. Infront of protoxylem cells lack casparian strips. These are called passage cells/transfusion cell.
  • Endodermis acts as a water tight jacket.
  • Pericycle is single layered and composed of prosenchyma
  • Lateral roots originate from pericycle. Adventitious roots originate from phloam parenchymal(endogonous)
  • Vascular  bundle are radial and exarch.
  • Pith is absent or less.

- wherein

Internal Structure (Anatomy) of Dicot Roots

 

 Structure of protoxylem is highly different.


Option 1)

Secondary xylem

Incorrect Option

Option 2)

Secondary phloem

Incorrect Option

Option 3)

Protoxylem

Incorrect Option

Option 4)

Cortical cells

Incorrect Option

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Aadil

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