Master GCSE Biology

MS1.

- Aseptic technique is a set of procedures used to prevent contamination (1)

- It is essential to minimize the risk of introducing bacteria or other microorganisms (1)

MS2.

- Use the correct magnification/eyepiece (1)

- Adjust the stage and fine focus knob to focus the specimen (1)

MS3.

- Benedict's reagent is a blue solution that turns green/yellow/orange/red in the presence of reducing sugars (1)

- Reducing sugar: glucose, fructose (any one) (1)

MS4.

- Protein (1)

MS5.

- Variables to control: the concentration of the solution, temperature, surface area of the membrane (any two) (1)

- Controlling variables ensures a fair test and allows for accurate comparisons (1)

MS6.

Reliability:

- Repeating the investigation multiple times (1)

- Using the same equipment and methods (1)

Validity:

- Using appropriate controls (1)

- Ensuring the investigation tests what it claims to test (1)

MS7.

- To distinguish between starch and other types of carbohydrates (1)

MS8.

- Independent variable: the factor being changed or manipulated by the experimenter (1)

- Dependent variable: the factor that changes in response to the independent variable (1)

MS9.

Sources of error:

- Human error (1)

- Equipment failure (1)

Minimizing impact:

- Careful observation and recording (1)

- Calibrating equipment before use (1)

MS10.

- Accuracy: how close a measurement is to the true value (1)

- Precision: how close repeated measurements are to each other (1)