1. 1
   A doctor examines a blood sample from a patient with anaemia and notes that the patient's red blood cells appear smaller and paler than normal, reducing their ability to carry oxygen efficiently around the body.

   (a)

   Which shape of red blood cell increases the surface area available for oxygen absorption?

   [1 mark]

   • ASpherical
   • BBiconcave disc
   • CCuboidal
   • DElongated with a tail

   (b)

   Which other adaptation allows healthy red blood cells to carry more oxygen than the patient's affected cells?

   [1 mark]

   • AThey contain no nucleus, leaving more space for haemoglobin
   • BThey contain a large nucleus
   • CThey contain many mitochondria
   • DThey contain chloroplasts

   (c)

   Describe two adaptations of a healthy red blood cell that allow it to carry out its function of transporting oxygen efficiently.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A fertility specialist compares a sperm cell and an egg cell taken from a couple trying to conceive, noting clear differences in size, structure and mobility between the two types of gamete.

   (a)

   Which structure helps the sperm cell to swim towards the egg cell?

   [1 mark]

   • AA large food store in the cytoplasm
   • BCilia covering the whole cell surface
   • CA cell wall
   • DA tail (flagellum)

   (b)

   Which adaptation of the egg cell provides nutrients for the early embryo after fertilisation?

   [1 mark]

   • AA tail (flagellum)
   • BMany mitochondria concentrated at the tail base
   • CA large cytoplasm containing food (nutrient) stores
   • DEnzymes stored in the acrosome

   (c)

   Describe how the sperm cell is adapted for its function of reaching and fertilising the egg cell.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A doctor explains to a patient who smokes that cigarette smoke damages the ciliated epithelial cells lining the trachea and bronchi, reducing their ability to protect the lungs from dust and pathogens.

   (a)

   Explain how ciliated epithelial cells are normally adapted to protect the lungs from dust and pathogens, and how smoking damages this function.

   [3 marks]

   (b)

   Using the trachea and lungs as examples, describe the levels of organisation from cells to organ systems in the human body.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Early plant biologists studying root and leaf tissue under the microscope identified several cell types specialised for very different roles within the same plant, and organised these observations into a hierarchy from cells to whole organisms.

   (a)

   Describe how root hair cells and palisade cells are each specialised for their functions in the plant.

   [6 marks]

   (b)

   Describe the levels of organisation from cells to organism, giving an example of a tissue, an organ and an organ system in both a plant and an animal.

   [6 marks]

   Total for question 4: 12 marks

End of questions