# One- and two-mark questions

One- and two-mark questions will start with command words such as 'Describe...' or 'Explain...'. Some command words are easy to understand such as:

• 'Calculate...' or 'Determine...' for maths questions
• 'Complete...' to fill in a gap in a table or graph
• 'Define...' to give the meaning of an important word
• 'Suggest...' where you use your knowledge in an unfamiliar situation

The command words 'Describe...' and 'Explain...' can be confusing. If you are asked to describe a graph, you will be expected to write about its overall shape, whether it is linear or curved, the slope of gradients etc. If you are asked to explain why a pattern or trend is seen in a graph, you will be expected to use your science knowledge, not just say what you see (which is a description), eg The graph shows a steep linear increase for the first three hours because…

Explain how and why questions often have the word 'because' in their answer. Describe questions don't.

The number of marks per question part is given in this form [2 marks]. It is essential that you give two different answers if a question is worth two marks. Sometimes you can gain a second mark by giving the units in a calculation or stating specific data points, eg the mass of the plant tissue decreased by 2 g.

These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.

## Sample question 1 - Foundation

Question

Use one word from the box to complete the sentence.

The structure in a cell that controls the cell's activities is called the _________

[1 mark]

 Cell membrane Cytoplasm Mitochondrion Nucleus

Nucleus

## Sample question 2 - Foundation

Question

Give two differences between plant and animal cells.

[2 marks]

Answer (any two of):

• plant cells have a cell wall, animal cells do not
• plant cells have permanent vacuoles, animal cells do not
• plant cells have chloroplasts, animal cells do not

## Sample question 3 - Higher

Question

Name the type of cell in plants that can differentiate into different types of cell.

[1 mark]

Meristem cell or meristematic cell.

Note that you must be specific. It isn’t enough to call it a 'stem cell', as stem cells occur in animals.

## Sample question 4 - Higher

Question

In an osmosis experiment, after 45 minutes, a potato cylinder had lost 2.4 g in mass.

Calculate the rate of water loss from the potato cylinder in grams per hour.

[2 marks]

• 3.2 g h-1
• 45 minutes = 0.75 h
• the water lost in 0.75 h is 2.4 g, therefore:
• $$\frac{2.4}{0.75}$$ of water would be lost in one hour
• the rate of water loss is 3.2 g per hour, or written more scientifically, 3.2 g h-1

Note that rate is a and always has more than one unit.