Required Practicals_GCSE_Variable (know your IV, DV and CV)

Quiz by Mr R Horn

Our brand new solo games combine with your quiz, on the same screen

Correct quiz answers unlock more play!

25 questions
• Q1

A variable is any factor that may change (vary)

eg temperature, concentration, rate of reaction, mass, volume

true
false
True or False
30s
• Q2

In an experiment, what is meant by the 'independent variable'?

The factor that is measured

A factor that must be kept constant (to ensure validity)

The factor that is (intentionally) changed/selected by the investigator

30s
• Q3

In an experiment, what is meant by the 'dependent variable'?

The factor that is (intentionally) changed/selected by the investigator

The factor that is measured

A factor that must be kept constant (to ensure validity)

30s
• Q4

In an experiment, what is meant by the 'control variable'?

The factor that is (intentionally) changed/selected by the investigator

A factor that must be kept constant (to ensure validity)

The factor that is measured

30s
• Q5

Variables may be 'continuous' or 'categoric'.

(Continuous = can be measured / may be any numerical value)

(Categoric = can be described/labelled. Fits into groups/categories)

Sorting
30s
• Q6

How should you adjust the microscope to increase the magnification of the image?

Change the objective lens to a higher magnification lens

Turn the coarse focusing wheel

Move the stage further away from the lens

Zoom in

30s
• Q7

Ribosomes can be viewed using an electron microscope. However, they cannot be viewed using a light microscope. Explain why.

Electron microscopes have a higher magnification and resolution

Light microscopes cannot be adjusted to focus in closely enough

30s
• Q8

image size = real (actual) size  x  magnification

A root hair cell was viewed at a magnification of ×50

The image length of the root hair X–Y is 43 mm

Calculate the real length of the root hair in micrometres (µm).

2150µm

1.16mm

860µm

0.86mm

30s
• Q9

How should you adjust the microscope to obtain a clearer image?

Change the objective lens to a higher magnification lens

Turn the coarse/fine focusing wheel

Zoom in

Use a brighter light source

30s
• Q10

An experiment investigated the effect of sugar concentration on the mass of potato cylinders.

What is the independent variable?

The change in mass of the potato cylinders

The length of time that the cylinders were left in the solutions

The concentration of the sugar solution

30s
• Q11

An experiment investigated the effect of sugar concentration on the mass of potato cylinders.

What is the dependent variable?

The length of time that the cylinders were left in the solutions

The change in mass of the potato cylinders

The concentration of the sugar solution

30s
• Q12

An experiment investigated the effect of pH on the rate of reaction of amylase enzyme.

Which is the independent variable?

The rate of reaction of amylase

Temperature

The pH

30s
• Q13

An experiment investigated the effect of pH on the rate of reaction of amylase enzyme.

Which is a control variable?

The pH

The rate of reaction of amylase

Temperature

30s
• Q14

An experiment investigated the effect of light intensity on the rate of photosynthesis using pondweed (eg Elodea).

Which is the independent variable?

The light intensity

The rate of photosynthesis (measured by counting the number of bubbles of O2)

Temperature

30s
• Q15

An experiment investigated the effect of light intensity on the rate of photosynthesis using pondweed (eg Elodea) by counting the number of bubbles released in 1 minute.

How could the investigator measure the rate of photosynthesis more accurately?

Measure the volume of gas released  in 1 minute

Measure the change in mass of the pondweed in 1 minute

Place the pondweed further from the light source

Count the number of bubbles released in 30s.

30s

Teachers give this quiz to your class