6.2 The Blood system

1.The diagram shows red blood cells and undifferentiated tissue cells. [Source: © International Baccalaureate Organization 2017] Diffusion of oxygen from blood cells to tissue cells is represented by arrow 3 in the diagram. What molecules are shown diffusing by arrow 1 and arrow 2?

2. Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is based on DNA sequences and the cladogram on the right is based on comparing protein sequences. What is the reason that cladograms based on DNA sequences are more reliable predictors of the phylogenetic relationship of species than cladograms based on protein sequences?

3. In which blood vessel connected to the heart does blood have the lowest carbon dioxide concentration?  

4. What helps to keep blood flowing onwards away from the heart in an artery?

5. What is a feature of the left atrium?

6. The diagram shows the human heart. Which shows the sequence of blood flow in the heart?

7. The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive system. The graph shows the percentage of samples in which this bacterium showed resistance to six antibiotics over a period of ten years. What is a possible explanation for the total percentage resistance being larger than 100% in 2010?

8. What is the position of heart valves when blood pressure is highest in the aorta?

9. The diagram shows changes of pressure during the cardiac cycle.   Which is an explanation of the processes happening?

10. Which discovery was an indication that the heart pumps blood to the body through arteries?

11. Which is a valid comparison between arteries and veins?  

12. What causes heart ventricles to fill with blood? I.  Atrial contraction II. Closing of atrioventricular valves III. Opening of semilunar valves

13. When the left ventricle is relaxed, what is the state of the valves?

14. What causes heart ventricles to fill with blood? I. Atrial contraction II. Closing of atrio-ventricular valves III. Opening of semilunar valves

15. What is a role of the coronary arteries?  

16. What is a feature of the human circulatory system?  

17. What is a role of the coronary arteries?

18. The diagram below shows the human heart. What structures are indicated by the labels X, Y and Z?

19. What is dissolved in blood plasma?

20. What is the state of the atrio-ventricular and semilunar valves when the left ventricle contracts?

21. What is the state of the atrio-ventricular and semilunar valves when the left ventricle contracts?

22. What are the conditions of the blood travelling through the pulmonary vein?

23. What causes the rate of heart contraction to increase or decrease?  

24. What is the function of thrombin in the process of blood clotting?

25. What is the direction of flow of oxygenated blood during a heartbeat?

26. What is a similarity between arteries and capillaries?

27. How is epinephrine (adrenaline) carried to the pacemaker of the heart and what effect does it have on heartbeat rate?

28. What is the condition of the valves of the heart when the right ventricle is contracting?

29. Which blood vessel directly supplies oxygen to the heart muscle?

30. This question refers to the following diagram of the heart. What is the structure labelled X?

31. What is a role of the coronary arteries?

32. What is the role of the pacemaker (SAN)?  

33. Is the blood in the aorta, left ventricle and pulmonary artery oxygenated or deoxygenated?

34. Which vessel directly supplies the heart muscle with blood?

35. Is the blood in the aorta, left ventricle and pulmonary artery oxygenated or deoxygenated?

36. The diagram below shows the human heart. What structures are indicated by the labels X, Y and Z?

37. What is a correct pathway for blood flowing through the heart?  

38. What is a role of the pacemaker or sinoatrial node (SAN)?  

39. What route does blood follow to supply oxygen to heart muscle?

40. Which of the following describes arteries?