What each biology required practical does, food test colours, hazards, improvements and planning.
What you will learn
- Say what each required practical measures
- Interpret food test results
- Plan an investigation
The practicals at a glance
Microscopy, osmosis, food tests, enzymes and pH, photosynthesis, reaction time, field investigations (plus culturing microorganisms, plant responses and decay for separate Biology).
| Test | Positive result | Shows |
|---|---|---|
| Benedict's, heated | brick red | reducing sugar |
| iodine | blue-black | starch |
| biuret | purple | protein |
| ethanol, then water | cloudy white | lipid |
Before a practical, a risk assessment lists each hazard (something that could cause harm, such as bacteria that might be pathogens, a hot water bath or sodium hydroxide in biuret) and the precaution for it.
The rest of this lesson and its 8 practice questions are locked.
In this lesson
- The practicals at a glance
8 practice questions, marked as you go; about 20 minutes in all.
Key terms
Risk assessment, Hazard
In this unit: Required practicals and maths skills
The skills behind every biology practical: units and magnification, means and percentages, rates and graphs, sampling, ratios and planning.