Experiment 12 Biology Stpm Page

"Describe an experiment to demonstrate totipotency in plants. Discuss how the ratio of auxin to cytokinin influences morphogenesis. [15 marks]"

| Error | Precaution | |-------|-------------| | Air bubbles present initially | Cut plant underwater | | Temperature increase from lamp | Place a beaker of water between lamp & plant | | Inconsistent disc size | Use same punch size for filter paper | | CO₂ depletion | Use fresh NaHCO₃ solution each time | experiment 12 biology stpm

The core concept linking Experiment 12 to the theory is that even differentiated plant cells retain all genetic information needed to form a complete organism. "Describe an experiment to demonstrate totipotency in plants

| Category | Items | | :--- | :--- | | | Young, healthy Chrysanthemum leaves or Daucus carota (carrot) root. | | Culture Medium | MS medium powder, sucrose (30g/L), agar (8g/L), distilled water. | | Growth Regulators | 2,4-D (2,4-Dichlorophenoxyacetic acid – an auxin), BAP (Benzylaminopurine – a cytokinin). | | Sterilization agents | 70% ethanol, 0.1% mercuric chloride (or 10% Clorox), sterile distilled water. Tween-20 detergent. | | Equipment | Laminar air flow cabinet, autoclave (or pressure cooker), forceps, scalpels (#11 blade), spirit lamp, Parafilm, Petri dishes, culture tubes or magenta boxes. | | Glassware | Measuring cylinders, conical flasks (250 ml & 500 ml), pH meter or pH paper. | | Category | Items | | :--- |