Fig. 3.1a is a diagram of the human skeleton. Fig. 3.1b is an X-ray that shows damage to part of a person's skeleton. [Figure 3.1a] [Figure 3.1b] (b) Fig. 3.2 shows the arrangement of bones and muscles in part of a person's body. [Figure 3.2] (c) Fig. 3.3 shows the approximate percentage of body mass that is due to the skeleton in birds and in humans. [Figure 3.3]

1. (a)(i)Draw the letter X on Fig. 3.1a to show the location of the damage to the person's skeleton that is shown in Fig. 3.1b.[1]
2. (a)(ii)Describe the damage to the person's skeleton shown in Fig. 3.1b.[2]
3. (b)(i)Name the muscle labelled B in Fig. 3.2.[1]
4. (b)(ii)Draw an arrow on Fig. 3.2 to show the direction of movement that will be caused when the muscle labelled B contracts.[1]
5. (b)(iii)When the muscle labelled B contracts, the muscle labelled A relaxes. State the term that refers to a pair of muscles that act in this way.[1]
6. (c)(i)Use the information in Fig. 3.3 to compare the approximate percentage of body mass that is due to the skeleton in birds and in humans.[1]
7. (c)(ii)One reason for this difference is that the bones of a bird contain air spaces. These air spaces are connected to the lungs of the bird. The blood of birds contains more haemoglobin per unit volume than that of humans. Suggest how these adaptations, and that shown in Fig. 3.3, help a bird to move by flying.[4]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.