Practical Skills(WJEC)

Iodine Solution

Iodine Solution

Used to stain plant cells (onion cells) for better visualization of cell structures.

Methylene Blue Solution

Utilized to stain animal cells (cheek cells) to enhance the visibility of cell structures.

Cover Slip Technique

Essential to prevent air bubbles that can obstruct the view of cells under the microscope.

Objective Lenses

Begin with low power (10X) for general observation, then switch to high power (40X) for detailed examination.

Labeled Drawings

Include all visible cell structures like cytoplasm, cell membrane, nucleus, and cell wall in the diagrams.

Energy Content of Food

Measure the energy content by heating and recording the water temperature change.

Controlled Variables

Maintain consistent water volume and fixed tilting angle for accurate results.

Sources of Error

Heat loss and incomplete combustion can affect the precision of energy content measurements.

Enzymes

Investigate the effect of temperature on enzyme activity using amylase and starch solutions.

Rate Calculation

Calculate the rate of enzyme reaction as 1 divided by the time taken for the iodine to remain brown.

Photosynthesis

Study the impact of light on photosynthesis by measuring oxygen bubble production in pondweed.

Transpiration

Explore factors affecting transpiration rates in plants using a potometer and varying environmental conditions.