BISHOP S CONSERVATORY SCHOOL ANNUAL EXAMINATIONS FORM 4 BIOLOGY TIME: 1hr 30 min. Section B

Size: px

Start display at page:

Download "BISHOP S CONSERVATORY SCHOOL ANNUAL EXAMINATIONS FORM 4 BIOLOGY TIME: 1hr 30 min. Section B"

Patrick Hudson
5 years ago
Views:

BISHOP S CONSERVATORY SCHOOL ANNUAL EXAMINATIONS 2006 FORM 4 BIOLOGY TIME: 1hr 30 min INDEX NUMBER Total: 100 marks Section A Answer all questions in this section. Section A carries 55 marks.

1 BISHOP S CONSERVATORY SCHOOL ANNUAL EXAMINATIONS 2006 FORM 4 BIOLOGY TIME: 1hr 30 min INDEX NUMBER Total: 100 marks Section A Answer all questions in this section. Section A carries 55 marks. Question Number Section A Section B Max mark Actual mark The table below shows some animals and examples of the food they eat. Animal Food the animal eats Lacewing fly Greenfly Small birds Fox Weasel Vole Hawk Lacewing; caterpillars Small birds; voles Voles Plants Small birds a) Fill in the boxes A, B, C and D in the food web, which follows, with the names of animals from the Table above. (2 marks) Page 1 of 11

2 b) Where does the energy flowing through this food web come from? (1 mark) c) Which organisms can make use of the energy supplied by the source named in (b)? (1 mark) d) Using the food web given above, construct a food chain which includes five (5) organisms in it. (1 mark) e) Describe what happens to the plants and to the small birds if an insecticide was sprayed in the area and killed all the primary consumers. (2 marks) f) Explain the role of decomposers in the system. (1 mark) 2. An investigation was carried out to study the effect of light on the rate of photosynthesis in a Canadian pondweed (Elodea). The apparatus was set up as shown in the diagram. The student doing the investigation noted that when light shines on the shoot bubbles of gas are released. a) Name the gas you think is being released in this experiment. (1 mark) b) Briefly explain how you can find out if your answer to (a) is correct. (1 mark) Page 2 of 11

3 c) In the experiment a very weak solution of sodium hydrogen carbonate (sodium carbonate) was used instead of water. Suggest a reason for this. (1 mark) d) The experiment was repeated on a very bright day but at different times of the day. It was noticed that the rate at which bubbles were released varied according to the time of the day. Suggest one factor, besides temperature, that was most likely affecting the rate at which the gas was being evolved. (1 mark) e) Elodea is an autotrophic plant, while Mucor is a saprophytic fungus. Name the substance found in the cells of Elodea, but not in Mucor that enables it to have an autotrophic mode of life (1 mark) 3a) The drawing shows the teeth from part of the upper jaw of a gorilla. Match words from the list with the labels 1-4 on the drawing. (2 marks) canine tooth incisor tooth molar tooth premolar tooth b. Which of the 4 types of teeth is not found in an herbivorous mammal? (1 mark) Page 3 of 11

4 4a) Complete the word equation for aerobic respiration. oxygen + + (3 marks) b) Where in the human body does aerobic respiration take place? (1 marks) c) Complete the table to give two differences between aerobic and anaerobic respiration. (2 marks) Aerobic Respiration Anaerobic Respiration. 5. The kidneys are part of the body s homeostatic mechanism. a) Define homeostasis. (1 mark) b) The diagram shows a vertical section through the human kidney. Label the parts marked: A B C D E (5 marks) c) Name one difference between the contents of blood vessels C and D. (1 mark) d) Apart from the kidney, give the name of another organ involved in homeostasis and give its role (function) Organ (1 mark) Function (1 mark) Page 4 of 11

6) The graph shows the activity of two enzymes at a different ph. a) At which ph is enzyme A most active? (1 mark) b) Where in the digestive system is enzyme A found?

5 6) The graph shows the activity of two enzymes at a different ph. a) At which ph is enzyme A most active? (1 mark) b) Where in the digestive system is enzyme A found? (1 mark) Enzyme A Lipase c) What is the function of the enzyme lipase? (1 mark) ph 7) The diagram shows how carbon dioxide, containing radioactive carbon atoms, was supplied to a leaf attached to a plant stem. A small tube was inserted into the stem at point X. Droplets of liquid from tissue B were collected from the tube. a) (i) Name tissue A, which carries water and minerals from the roots. (1 mark) (ii) Name tissue B. (1 mark) Page 5 of 11

6 b) This experiment is used as an evidence for translocation. Give the meaning of the word translocation. (1 mark) c) Very briefly explain another experiment that can be used as evidence of translocation in plants. (1 mark) d) When radioactive carbon dioxide was supplied during daylight, the droplets of liquid, which appeared at X, were radioactive. The droplets were not radioactive when radioactive carbon dioxide was supplied in the dark. Explain these observations. (1 mark) 8) The diagram below shows sections drawn through three different kinds of blood vessels. a) Give the name of vessel C (1 mark) b) Give two ways in which vessels A and B differ in their structure. (2 marks) c) How might a diet containing excess fats affect the structure of vessel A? (1 mark) Page 6 of 11

7 d) The diagram shows a drawing of a blood sample observed under the light microscope. i) Give the function of cells 1 and 3: cell 1 - cell 3 - (2 marks) ii) Name structure 4 and say why it is important. (2 marks) iii) Name a substance apart from the blood cells and structures shown above that is carried by the blood part shown by the number 2 (1 mark) 9) Read the following statement and then answer the questions below: Your diet should provide you with energy, materials for growth and metabolism, enough water and sufficient indigestible bulk to help you pass food along the gut. a) Name the type of food that provides most energy: (1 mark) b) Which food type is required for: i) muscle and tissue growth: (1 mark) ii) providing bulk so that food can move smoothly in the digestive system (1 mark) c) Water has many important functions in the body. Give two of them. (2 marks) Page 7 of 11

8 d) Vitamins and minerals are also important in maintaining a healthy body. Name any vitamin or mineral of your choice and say why it is needed in the body. Vitamin/Mineral Function (2 marks) THIS IS THE END OF SECTION A Section B Answer question 1 and any TWO others from this section. This section carries 45 marks. (In all you must answer three 3 questions.) 1. Read the following passage carefully and then answer the questions that follow. Rennet and cheese making Cheese is usually made from pasteurized milk. Milk used for cheese making is obtained from cows, goats, sheep and even buffalo. The taste can be affected by the grass the animals have eaten and the soil type. The cheese-maker adds a culture of a harmless bacterium to start the process off. The bacterium (Streptococcus lactis) uses the lactose sugar in the milk as a food supply and converts it into lactic acid, lowering the ph of the milk to about An enzyme preparation, called rennet, is then added. This catalyses changes in the milk proteins causing them to form a gel (curd) and separate from the watery whey. Page 8 of 11

9 The main proteins in milk are called caseins. Casein molecules group together in milk to form very small particles called micelles, which give milk its cloudy appearance. Each micelle contains about 500 casein molecules. The rennet catalyses the hydrolysis of parts of the casein molecule so exposing particularly sticky regions on the surface of the micelles. These regions attract each other and bring many micelles together as the curd. Rennet is extracted from the stomach of calves that are at an age where they still rely on their mother s milk. The calves must be slaughtered first and must be no older than 32 days. This traditional rennet is in short supply: over the last thirty years the slaughter of calves has decreased, and at the same time the demand for cheese has increased. Rennet contains the enzyme chymosin, so biochemists have looked for an alternative supply of an enzyme with similar characteristics. They have tried many protein digesting enzymes from microbes, but few have the ability to catalyse only the limited break-down of casein that chymosin manages. Some species of mould produce an acid protease enzyme that has proved successful. a. What are enzymes? (2 marks) b. Mention two factors that may affect the rate of an enzyme controlled reaction. (2 marks) c. Enzymes are said to be substrate specific. Explain with the help of diagrams. (3 marks) d. Why is the bacterium Streptococcus lactis added to the pasteurized milk at the beginning of the cheese making process? (1 mark) e. What happens to the milk when the enzyme preparation is added? (1 mark) f. What are micelles? (1 mark) g. From where is rennet obtained, and why is it in short supply? (1,2 marks) h. Name the enzyme found in the Rennet preparation. (1 mark) i. Cheese making is one of the industrial uses of anaerobic respiration. Mention another industrial use of anaerobic respiration (1 mark) (Total 15 marks) Page 9 of 11

10 2. a) Draw a well-labelled diagram to show the structures through which air from outside passes to reach the alveoli in your lungs. (5 marks) b) Explain why breathing through the nose is healthier than breathing through the mouth. (2 marks) c) How is food prevented from entering the trachea? (1 mark) d) State three characteristics of a good respiratory surface. (3 marks) e) Explain with the help of diagrams how gas exchange occurs in fish or insects. (4 marks) (Total 15 marks) 3) a) Explain why single-celled organisms do not need a transport system. (1 mark) b) Draw and label a diagram of a section through a human heart showing the four main chambers and the blood vessels which enter or leave them. On your diagram show the thickness of the walls of the chambers and the position of the main heart valves. (5 marks) c) The average human heart beats about 60 to 70 times per minute at rest. Suggest and explain two reasons why a person s heart beat might be considerably higher or lower than this at times. (3 marks) d) Give three differences between the structures of xylem and phloem tubes. (3 marks) e) Describe with the help of a diagram how water in soil is transported into roots. (3 marks) (Total 15 marks) 4) a. What is meant by the terms: i. Digestion ii. Egestion iii. Assimilation? (3 marks) b) A patient had a blocked bile duct as a result of gall stone formation (known as āebla in Maltese). How would this affect the process of digestion? (2 marks) c) Food does not actually pass from the pancreas and yet it is important in the digestive process. Explain clearly the importance of the pancreas in digestion. (2 marks) Page 10 of 11

11 d) A student wants to test for the presence of starch in boiled potatoes. Describe an experiment she would have to perform in order to do this. Include any observations if the test is positive. (3 marks) e) Food substances must be absorbed into the blood before they can be used by body cells. List three ways in which the small intestine of a human is adapted for efficient absorption. (3 marks) f) Single celled organisms like Amoeba also need to feed. Explain with the help of diagrams the feeding mechanism in Amoeba. (2 marks) (Total 15 marks) 5. Some organisms can regulate their body temperature while others cannot. a) What are organisms that can maintain a constant body temperature called? Give one example. (2 marks) b) What are organisms that cannot maintain a constant body temperature called? Give one example. (2 marks) c) Blood capillaries, hairs and sweat glands in the skin of humans play an important role in this process. Describe how each of these structures is involved in maintaining a constant body temperature in both cold and warm environments. Present your answer in table form. A table similar to the one below can be used. (Write on a separate sheet) Cold environment Warm environment Blood Capillaries Hairs Sweat Glands d) Draw a large labelled diagram of the human skin (5 marks) (6 marks) (Total 15 marks) Page 11 of 11

HOLIDAY HOMEWORK - CLASS VII BIOLOGY

HOLIDAY HOMEWORK - CLASS VII BIOLOGY HOLIDAY HOMEWORK - CLASS VII Respiratory System Vocabulary BIOLOGY Instructions: Use the word bank to complete each statement about the respiratory system. Word Bank: alveoli; bronchiole; carbon dioxide;