AQA GCSE (9-1) Bio Grade 6_7

Section 1: Cell biology

Plant and animal cells (eukaryotic cells) 1.

The diagram shows an animal cell.

A

a Which letter shows the structure responsible

E

for controlling substances entering and leaving the cell?

[1 mark]

D B

C

b Which structure(s) can only be seen with an

electron microscope?

[1 mark]

Part C:

[1 mark]

Function:

[1 mark]

c Identify part C. What is the function of part C?

2.

a What are plant cell walls made of?

[1 mark]

b State three functions of a plant cell wall.

1

[1 mark]

2

[1 mark]

3

[1 mark]

3.

a Name this organelle.

b Write down the name of one type of cell where many of these

[1 mark] length

organelles are found.

[1 mark]

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1 c The organelle has been magnified 12 000 times.

Maths

Calculate the actual length of this organelle in μm.

Worked Example

[3 marks]

Length on diagram = 15 mm real size =

size of image 15 = magnification 12 000 = 0.00125 mm

The student gets all 3 marks for this answer. They have measured the length of the image and used the correct formula to work out the real size of the organelle. They have converted mm to μm correctly by multiplying by 1000 – because there are 1000 μm in 1mm.

= 1.25 μm

Bacterial cells (prokaryotic cells) 1.

Which of the following statements are true? Tick two boxes.

Bacteria are easily seen under a light microscope with low power.

Bacterial cell walls are not made of cellulose.

Bacterial cells contain DNA in a nucleus.

Bacteria contain loops of DNA called plasmids.

2.

[2 marks]

The diagram shows a bacterial cell. a Name structure A and state its function.

A

Structure A: Function:

[1 mark] [1 mark]

b Which group of organisms do bacteria belong to?

[1 mark]

[1 mark]

[1 mark]

c What is the outside coating on some bacterial cell walls?

d Why is this coating important?

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