Class XII Practical: Slide Preparation - T.S. of Hydrophyte Stem

Objective

To prepare a temporary transverse section (T.S.) of a hydrophyte (aquatic plant) stem and observe its anatomical adaptations to an aquatic environment.

Guidelines

1. Specimen Selection: Obtain a fresh stem of an aquatic plant (e.g., Hydrilla, Nymphaea, Eichhornia).
2. Sectioning: Carefully cut very thin transverse sections of the stem using a sharp blade.
3. Staining (Optional): Stain the sections with a dilute stain like safranin or methylene blue.
4. Mounting: Mount the stained section in a drop of water on a clean glass slide and cover with a coverslip.
5. Observation: Observe the slide under a compound microscope. Look for characteristic adaptations:
   • Reduced Vascular Tissue: Less developed xylem and phloem.
   • Large Air Chambers (Aerenchyma): Extensive air spaces for buoyancy and gas exchange.
   • Thin Cuticle/Absent Stomata: Reduced need for water conservation.
   • Poorly Developed Mechanical Tissues: Less need for support in water.
6. Drawing: Draw a neat, labeled diagram of the observed T.S. of the hydrophyte stem, highlighting its adaptive features.

Expected Outcome

Clear microscopic observation of anatomical features in a hydrophyte stem that facilitate survival in an aquatic habitat.