Class XI Practical: Cytology - T.S. of Monocot & Dicot Roots

Objective

To prepare and observe temporary transverse sections (T.S.) of monocotyledonous and dicotyledonous roots to study their anatomical differences.

Guidelines

1. Sectioning: Obtain fresh monocot (e.g., maize, onion) and dicot (e.g., gram, pea) roots. Cut very thin transverse sections using a sharp blade.
2. Staining: Stain the sections with appropriate stains (e.g., safranin and fast green).
3. Mounting: Mount the stained sections in glycerine or water on a clean slide and cover with a coverslip.
4. Observation: Observe the slides under a compound microscope. Identify and compare:
   • Root Cap: Protective layer at the tip (if whole root tip is used).
   • Epidermis: Outermost layer, often with root hairs.
   • Cortex: Broad region of parenchyma cells.
   • Endodermis: Innermost layer of cortex with Casparian strips.
   • Vascular Bundles: Arrangement (radial), number of xylem and phloem bundles (polyarch in monocots, di- to hexarch in dicots), presence/absence of pith.
5. Drawing: Draw neat, labeled diagrams of both monocot and dicot root T.S., highlighting key differences.

Expected Outcome

Clear understanding and ability to differentiate between the internal anatomical structures of monocot and dicot roots.