Cell structure and organellesIB MYP Biology: Subtopic test

1. 1
   A sports scientist is studying cells taken from the leg muscle of a marathon runner and from the lining of the runner's cheek. Under the microscope she sees that the muscle cells contain far more mitochondria than the cheek cells.

   (a)

   Which process takes place in the mitochondria?

   [1 mark]

   • APhotosynthesis, which makes glucose
   • BAerobic respiration, which releases energy
   • CProtein synthesis, which joins amino acids together
   • DStorage of the cell's genetic material

   (b)

   Where is the genetic material found in a muscle cell?

   [1 mark]

   • AThe ribosomes
   • BThe cell membrane
   • CThe cytoplasm
   • DThe nucleus

   (c)

   Explain why the muscle cells contain many more mitochondria than the cheek cells.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student compares a cell from the leaf of a pondweed plant with a cell from the lining of a human cheek. The pondweed cell has a rigid, regular outline, large green structures and a large fluid-filled space. The cheek cell is irregular in shape and has none of these features.

   (a)

   Which structure is found in the pondweed cell but not in the human cheek cell?

   [1 mark]

   • APermanent vacuole
   • BNucleus
   • CRibosomes
   • DCell membrane

   (b)

   What is the main function of the cell wall in the pondweed cell?

   [1 mark]

   • ATo control which substances enter and leave the cell
   • BTo release energy from glucose
   • CTo support the cell and keep its shape
   • DTo contain the genetic material

   (c)

   Describe the function of the chloroplasts and of the cell wall in the pondweed cell.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A student wants to find out whether cells in different parts of a plant contain different structures. She makes microscope slides of a green leaf and of a white root from the same potted plant and views both with a light microscope. She notices that the leaf cells contain many green structures but the root cells seem to contain none.

   (a)

   State a testable hypothesis about the number of chloroplasts in leaf cells and root cells, with a scientific reason, and identify the independent variable.

   [3 marks]

   (b)

   Outline how the student could collect reliable data, identifying the dependent variable and two control variables.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A pharmaceutical company has developed a new antibiotic that stops bacteria from building their cell walls. The drug is safe for patients and is used to treat bacterial infections. Some doctors warn, however, that prescribing antibiotics too often is helping bacteria to become resistant to them.

   (a)

   Explain, using the structures of bacterial cells and human cells, why the antibiotic can kill bacteria without harming the patient's own cells.

   [6 marks]

   (b)

   Discuss whether doctors should prescribe this antibiotic for every minor infection.

   [6 marks]

   Total for question 4: 12 marks

End of questions