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Figure 3 shows ciliated epithelial cells from the airways of a human as seen using a light microscope - Edexcel - GCSE Biology: Combined Science - Question 2 - 2021 - Paper 1
Question 2
Figure 3 shows ciliated epithelial cells from the airways of a human as seen using a light microscope. (i) Draw the cell labelled A in the box below. Label three pa... show full transcript
Worked Solution & Example Answer:Figure 3 shows ciliated epithelial cells from the airways of a human as seen using a light microscope - Edexcel - GCSE Biology: Combined Science - Question 2 - 2021 - Paper 1
Step 1
Draw the cell labelled A in the box below. Label three parts of this cell on your diagram.
Answer
To answer this part, sketch a clear diagram of a ciliated epithelial cell. Make sure to label three key structures:
- Cilia: Tiny hair-like structures that help move mucus and trapped particles out of the airways.
- Nucleus: The control center of the cell that contains genetic material.
- Cytoplasm: The jelly-like substance where cellular processes occur.
Ensure your diagram accurately reflects the shape and structure of cell A.
Step 2
State the function of the ciliated epithelial cells in the airways of the human breathing system.
Answer
The main function of ciliated epithelial cells in the airways is to trap and transport mucus, which contains trapped dust, pathogens, and other particles, out of the respiratory tract. The coordinated movement of the cilia helps clear the airways, protecting the lungs from infection and irritation.
Step 3
Use information from Figures 4 and 5 to calculate the mean rate of respiration of the maggots in mm per minute.
Answer
To calculate the mean rate of respiration, observe the distance the drop of colored liquid moved towards the test tube in Figure 5. If it moved, for example, 3 cm in 10 minutes, convert this distance into mm (3 cm = 30 mm). Then, calculate the mean rate of respiration by dividing the total distance by the time taken:
.
Step 4
Describe a control for this investigation.
Answer
A suitable control for this investigation would involve placing a similar test tube setup without maggots under the same conditions. This would help establish whether any movement of the liquid is due to the respiration of the maggots or other factors like temperature or atmospheric pressure changes.