1. 1
   A student prepares a slide of cells scraped from the inside of their cheek and views it under a light microscope. They identify a nucleus, cytoplasm and a cell membrane, but see no cell wall or chloroplasts.

   (a)

   Which structure controls the entry and exit of substances into and out of the cheek cell?

   [1 mark]

   • ANucleus
   • BCytoplasm
   • CCell membrane
   • DRibosome

   (b)

   Which structure would NOT be found in the student's cheek cell?

   [1 mark]

   • ANucleus
   • BCytoplasm
   • CCell membrane
   • DChloroplast

   (c)

   State the function of the nucleus and the function of the cytoplasm observed in the cheek cells.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A greenhouse worker examines a leaf cell from a tomato plant under a microscope and compares it with an animal cell. The plant cell shows extra structures not seen in animal cells, including a cell wall, chloroplasts and a large, permanent vacuole.

   (a)

   Which structure in the tomato leaf cell is responsible for photosynthesis?

   [1 mark]

   • ACell wall
   • BChloroplast
   • CVacuole
   • DMitochondria

   (b)

   Which structure gives the tomato leaf cell a fixed shape and structural support?

   [1 mark]

   • ACell wall
   • BNucleus
   • CRibosome
   • DCytoplasm

   (c)

   Describe two structural differences between the tomato leaf cell and a typical animal cell.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A research team investigates using stem cells taken from a patient's bone marrow to treat a blood disorder. The cells are grown in the laboratory and encouraged to differentiate into different specialised cell types before being introduced back into the patient.

   (a)

   Explain what is meant by cell differentiation and why it is important for the development of specialised cells such as red blood cells and nerve cells.

   [3 marks]

   (b)

   Discuss two advantages and two disadvantages of using stem cells to treat this patient's blood disorder.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A cell biologist compares three specialised cells from living organisms — a human red blood cell, a human sperm cell, and a root hair cell from a plant — to investigate how each cell's internal structure is adapted to its specific function.

   (a)

   Describe the structure of a plant cell and an animal cell, using named examples, and explain the function of each structure you identify.

   [6 marks]

   (b)

   Using the examples of the red blood cell and the root hair cell, explain how cell differentiation allows specialised cells to be adapted for their specific functions.

   [6 marks]

   Total for question 4: 12 marks

End of questions