1 1 Complete the description of the immune system, using the words from the list. Each word may be used once, more than once or not at all. antibodies chemical antigens biological engulf hairs nails vaccines block mechanical The body has defences to protect against infectious diseases. Skin and ............................................... in the nose are ............................................... barriers. Some types of blood cell are involved in defending the body against infectious diseases. Some blood cells can produce ............................................... which can kill the pathogen. Other cells can ............................................... the pathogen in a process called phagocytosis. [4] [Total: 4] 2 2 The human immunodeficiency virus (HIV) infects and destroys lymphocytes. The number of lymphocytes in the blood of a person infected with HIV was measured over a period of 84 months. The results are shown in the graph. Describe the changes in the number of lymphocytes, over the 84 months following infection with HIV, shown in the graph. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [2] [Total: 2] 3 3 The diagram shows the human gas exchange system. The list shows the names of some of the parts of the human gas exchange system. alveolus bronchiole larynx bronchus rib diaphragm trachea Use the words from the list to label the diagram. You do not need to use every word. Write your answers on the answer lines provided in the diagram.. [5] [Total: 5] 4 4 Breathing involves the movement of the ribs and the diaphragm. Describe the process of inspiration. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [4] [Total: 4] 5 The box on the left contains the term ‘Respiration’. The boxes on the right contain sentence endings. Draw two lines to join the term ‘Respiration’ to two boxes on the right to make two correct sentences. always produces carbon dioxide. is necessary for diffusion. Respiration occurs only in animals. releases energy. uses glucose. [2] [Total: 2] 5 6 A scientist measured the mass of carbon dioxide produced by anaerobic respiration in yeast cells for 1200 minutes. The graph shows the results. State the name of one other product of anaerobic respiration in yeast cells. .................................................................................................................................................. [1] [Total: 1] 6 7 The kidneys filter blood, separate useful molecules from excretory wastes and control the water content of the blood. Diagram A is of a kidney tubule and associated blood vessels. The arrows show the direction of blood flow. Diagram B is a drawing of a vertical section through a cell from the lining of region 2 of the tubule. diagram A diagram B The structures labelled S on diagram B are microvilli. Explain the importance of the microvilli on the surface of these cells. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [2] [Total: 2] 8 Protein can be broken down into amino acids. State the name of the organ in the human body that breaks down excess amino acids. .................................................................................................................................................. [1] [Total: 1] 7 9 Define the term homeostasis. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [2] [Total: 2] 8 10 The eye is adapted for focusing on near and distant objects. The diagram shows the parts of the eye involved in focusing. The eye is focused on a distant object. Describe and explain the changes that occur in the eye when adjusting focus from a distant object to a near object. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [3] [Total: 3]
