Cells: structure, types and specialisation: practice

5 marksFoundation and Higher4.1.1.2, 4.1.1.1

A student looks at a leaf cell from a moss plant and a bacterial cell under a microscope.

.1

Which structure controls which substances enter and leave the moss cell?

[1 mark]

.2

Give two ways the genetic material in the bacterial cell is different from the genetic material in the moss cell.

[2 marks]

.3

The moss cell is 0.1 mm long. The bacterial cell is 2 µm long. Calculate how many times longer the moss cell is than the bacterial cell.

[2 marks]

4 marksFoundation4.1.1.2, 4.1.1.1

Animal cells, plant cells and bacterial cells contain different structures.

.1

What is the function of mitochondria?

[1 mark]

.2

Name the structure in a plant cell that absorbs light for photosynthesis.

[1 mark]

.3

Which two structures are found in a bacterial cell? Tick two boxes.

[2 marks]

5 marksFoundationRequired practical 014.1.1.2, 4.1.1.5

A student prepares a slide of onion skin cells to look at under a light microscope. She peels a thin layer of skin from inside an onion, lays it flat on a microscope slide in a drop of iodine solution, and lowers a cover slip on top.

.1

Suggest why the student used a thin layer of onion skin.

[1 mark]

.2

Give the reason for adding iodine solution.

[1 mark]

.3

Which objective lens should the student use first to find the cells?

[1 mark]

.4

The student drew one cell. Her drawing of the cell is 45 mm long. The magnification of the microscope is ×150. Calculate the real length of the cell in micrometres (µm). Use the equation: real size

= \dfrac{\text{image size}}{\text{magnification}}

[2 marks]

8 marksHigherRequired practical 014.1.1.2, 4.1.1.5

A student is asked to observe cheek cells and produce a scientific drawing of them. A cheek cell is an animal cell.

.1

Describe how the student should prepare a slide of cheek cells and use a light microscope to produce a labelled scientific drawing of the cells, with a magnification.

[6 marks]

.2

Another student labelled a cell wall on his drawing of a cheek cell. He said the cell wall controls what enters the cell. Explain why he is wrong.

[2 marks]

5 marksFoundation and Higher4.1.1.3, 4.1.1.4

Cells become specialised to carry out particular jobs.

.1

A muscle cell contains many mitochondria. Explain why.

[2 marks]

.2

Which statement describes cell differentiation?

[1 mark]

.3

Compare cell differentiation in animals with cell differentiation in plants.

[2 marks]

4 marksFoundation4.1.1.1

A biologist examines a cell with a cell wall, cytoplasm, ribosomes and a loop of DNA, but no nucleus.

.1

Explain why this is a prokaryotic cell.

[2 marks]

.2

Explain the functions of its ribosomes and cell membrane.

[2 marks]

4 marksFoundation and Higher4.1.1.3, 4.1.1.2

A root hair cell and a palisade cell come from the same bean plant.

.1

Explain why the root hair cell has a long extension but usually lacks chloroplasts.

[2 marks]

.2

Explain why the palisade cell has many chloroplasts and a large permanent vacuole.

[2 marks]

5 marksFoundation and Higher4.1.1.3

A normal sperm cell has 80 mitochondria. An abnormal sperm cell has only 20 mitochondria but an undamaged tail.

.1

Calculate the percentage reduction in mitochondria.

[2 marks]

.2

Explain why the abnormal sperm may be less likely to reach an egg.

[3 marks]

4 marksHigher4.1.1.4, 4.1.1.3

Two cells have the same chromosomes. One differentiates into a muscle cell and the other into a nerve cell.

.1

Explain how each cell becomes suited to its function.

[2 marks]

.2

Evaluate the claim that different shapes prove these cells have different genes.

[2 marks]

4 marksFoundation and Higher4.1.1.2

A student draws a plant cell with a wall but no cell membrane. The student labels a chloroplast as the site of aerobic respiration.

.1

Explain why both a wall and a membrane should be shown.

[2 marks]

.2

Explain how to correct the respiration label and why the cell still needs respiration.

[2 marks]