BP105T Practical Experiments & Viva Questions
Comprehensive practical laboratory experiments and frequently asked oral viva voce questions with model answers for Introduction to Pharmacognosy (BP105T) following PCI 2026 academic standards.
🔬 Prescribed Laboratory Practical Experiments
Morphological & Macroscopic Identification of Crude Drugs
Objective: Identify and record morphological features of Senna leaf, Cinchona bark, Ginger rhizome, and Fennel fruit.
Determination of Stomatal Number and Stomatal Index
Objective: Prepare leaf epidermal peel of Datura/Senna and calculate Stomatal Index using camera lucida/micrometer.
Determination of Total Ash and Acid-Insoluble Ash Values
Objective: Incinerate crude drug in a muffle furnace at 450°C and determine percentage total ash and acid-insoluble ash.
Preliminary Phytochemical Screening Tests for Alkaloids and Glycosides
Objective: Perform Mayer's, Dragendorff's, Borntrager's, and Keller-Kiliani chemical tests on herbal extract samples.
High-Yield Oral Viva Voce Questions & Model Answers
What is the difference between total ash and acid-insoluble ash?
Total ash measures all non-volatile inorganic matter; acid-insoluble ash measures siliceous material (sand, silica) indicative of earthy contamination.
Name four general identification tests for alkaloids.
Mayer's test (cream ppt), Dragendorff's test (orange-brown ppt), Wagner's test (reddish-brown ppt), and Hager's test (yellow crystalline ppt).
Why are leaves collected before flowering in medicinal plant harvesting?
Secondary metabolite concentration in foliage is highest prior to flowering, as nutrients shift to reproductive organs during bloom.