Unit 0 - Practical Skills

Independent Variable

The one thing you change on purpose in an experiment.

Dependent Variable

What you measure or observe in an experiment as a result of changing the independent variable.

Controlled Variables

All other factors that are kept the same to ensure a fair test.

Microscopic Organisms

Use 20,000 – 50,000 for experiment groups.

Small Organisms

Use 100 – 500 per group in experiments.

Medium Organisms

Use 50 – 100 per group for testing.

Large Organisms

Use 5 – 30 per group in experiments.

Experiment Duration for Small Organisms

1 – 2 weeks, as they reproduce quickly.

Experiment Duration for Larger Organisms

2 – 4 weeks.

Reliability and Validity

Repeat the experiment 3–5 times for each variable to improve reliability.

Burns from Hot Equipment

A hazard that requires precautions like using tongs and wearing goggles.

Non-toxic Marking

Methods used to mark organisms that do not affect their survival.

Using Digital Thermometers

For measuring temperature accurately in experiments.

pH Indicators

Tools like pH probes and litmus indicators used for measuring acidity.

Line Graph

Used for continuous data representation such as time.

Bar Chart

Used for discontinuous or categorical data.

Histogram

A graphical representation of frequency data.

Control Variable Check

Checking if controlled variables stayed constant during an experiment.

Repeat Trials

Conducting multiple repetitions to enhance data reliability.

Anomalous Results

Results that do not fit the expected pattern or trend in data.

Justify Your Conclusion

Using evidence from the data to support whether results support or refute a hypothesis.

Further Investigations

Proposals for new questions or experiments based on previous results.