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 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.