Gas Exchange in Humans (CIE IGCSE Biology: Co-ordinated Sciences (Double Award))

The following list contains structures found within the breathing system.

Using the numbers 1 - 5, sequence the structures to indicate the order in which air passes through them during an exhalation.

Place a tick (✓) in the Table 1 below to indicate the name of the organ which governs the activity of the human breathing system.

Table 1

Explain your choice.

State the reagent used to test for the presence of carbon dioxide (CO₂) in a sample of air, and the appearance of a positive result.

State the number of times more carbon dioxide (CO₂) is in exhaled air than in inhaled air.

Fig. 1 shows the human breathing system, with some of its organs labelled.

Fig. 1

Complete the table below to identify structures 1 - 6 in Fig. 1.

Fig. 2 shows two students working together in an experimental investigation into the human breathing system. 

The seated student has just completed a period of 5 minutes of vigorous exercise and is sitting down. His partner is taking measurements.

Fig. 2

Describe the two measurements being taken as shown in Fig. 2.

Fig. 3 shows a serving of boneless pork ribs as served in a restaurant.

The meat comes from the area between the ribs and the bones are removed before serving.

Fig. 3

Name the type of tissue that the meat in this dish comes from.