Experiment 12 Biology Stpm Jun 2026

To relate these structures to their functions as homeostatic organs.

2,4-D is a synthetic auxin that stimulates dedifferentiation of parenchyma cells into meristematic cells. It activates genes responsible for cell cycle progression (cyclins and CDKs) and inhibits differentiation, thereby promoting callus formation.

The liver is the largest internal organ and is composed of functional units called . Key Structures to Observe: experiment 12 biology stpm

Experiment 12 is more than a memory test—it is your gateway to understanding plant biotechnology. Mastering the aseptic technique, hormonal ratios, and callus observation prepares you for university-level research in agriculture, pharmacology, or genetic engineering.

This is phenolic browning due to oxidation of polyphenols released from cut cells. It is common in woody plants or stressed explants. To prevent this, add antioxidants like polyvinylpyrrolidone (PVP) or citric acid to the medium, or use dark incubation for first 2 weeks. To relate these structures to their functions as

To relate these structures to their biological functions, specifically and osmoregulation . 1. The Liver (Transverse Section)

| 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 | The liver is the largest internal organ and

: Sketch a small section at high magnification showing individual cells and nuclei.

A low-power outline showing the distribution of tissue layers without individual cells.