GRADE 11 LIFE SCIENCES PAPER 2 NOVEMBER 2014 MARKS: 150 TIME: 2:30

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1 1 GRADE 11 LIFE SCIENCES PAPER 2 NOVEMBER 2014 MARKS: 150 TIME: 2:30 INSTRUCTIONS AND INFORMATION 1. Answer all questions. 2. Number the answers correctly according to the numbering system used in this question paper. 3. Present your answers according to the instructions of each question. 4. All drawings should be done in pencil and labelled in blue or black ink. 5. Draw diagrams or flow charts only if ask to do so. 6. The diagrams or flow charts are NOT drawn to scale. 7. Do NOT use graph paper. 8. You may use a non-programmable calculator, protractor and compass. 9. Write neatly and legibly. SECTION A QUESTION Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A- D) next to the question number The following are characteristics of a micro organism i. reproduce only in a host cell ii. they are parasites iii. they produce their own food iv. most of them are pathogens Which of these characteristics is/are common to that of a virus? A. i, ii and iii B. ii, iii and iv C. i, ii and iv D. iii and iv only To which Kingdom do moss plants belong? A. Monera B. Protista C. Bryophytes D. Angiosperm Which of the following is a characteristic feature of mosses? A. Xylem B. Phloem C. Seeds D. Spores The diagram below represents a bacterial cell.

2 2 Which of the following represents parts 1, 2 and 3? A. Plasmid, flagellum, capsule B. Flagellum, capsule, plasmid C. Plasmid, capsule flagellum D. Capsule, plasmid, flagellum A young man stepped on a dirty rusty nail. The diagrams below show some of the bacteria isolated from the wound and arrange of antibodies that were already present in his body. The antibodies have a specific shape that binds with the antigen found on the surface of the bacteria. The bacterium most likely to cause a severe infection is A. M B. N C. O D. P The following factors contribute to global warming A. Destruction of wetlands and deforestation B. Deforestation and burning of fossil fuels C. Burning of fossil fuels and destruction of wetlands D. Solar energy and wind energy The following are some characteristics of angiosperms: i. do not need water for sperm to move to egg cells ii. contain well developed vascular bundles iii. have true roots, stems and leafs iv. bear seeds Which of the above statements allow them to survive on land? A. i. ii and iv B i and iv only B. I, ii, iii and iv D. none of the above

3 1.1.8 Seeds that are stored in seed banks can be used to: A. use for human consumption B. re-establish endangered or extinct species C. to feed cattle D. decrease biodiversity When an infection was treated with a new drug, the inflammation decreased. In a few patients the inflammation returned after one week. The probable reason for this is 3 A. the patient developed an allergic reaction to the drug B. the decrease in inflammation allowed the pathogens to become resistant to the drug C. the white blood cells were not functioning properly and therefore the inflammation returned D. a few pathogens resistant to the drug were present at the start of treatment, the drug could not kill them and so they reproduced Which one of the following represent a positive human impact on the environment? A. Pollution B. Conservation C. environmental degradation D. population explosion 1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to ) A disease causing organism The centralisation of neural and sensory organs in the head or front part of the body A measure of the total greenhouse gasses emissions through the activities of a country, organisation or a person in one year The type of fertilisation occurring in flowering plants A micro-organisms use in the manufacturing of beer and bread 10 x 2 = (20) Poisonous, radioactive, explosive flammable and carcinogenic waste produced by factories and some mines Food from crops that have been change genetically The sensible and careful use of resources so that they will be available to future generations A collective name for animals without a backbone The gradual change of a productive land into an increasingly arid one, losing all its vegetation and wildlife 10 x1 = (10) 1.3 Indicate whether each of the statements in COLUMN I applies to A only, B only, Both A and B or NONE of the items in CLOUMN II. Write A only, B only, Both A and B or NONE next to the question number.

4 4 Column I Column II The type of symbiotic relationship displayed by A. Parasitism plasmodium living in the liver of humans is B. Mutualism All organisms in this phylum is sessile A. Annelida B. Porifera A substance made of a weakened form of a disease A. Vaccine causing organism B. Antigen Reproduce through binary fission A. Virus B. Fungi Site constructed to dispose of waste A. Landfill B. Reservoir The cause/s for global warming A. Afforestation B. Solar energy Factor /s influencing the quality of water A. Alien Plants B. Thermal pollution Cause /s the destruction of the ozone layer A. Aerosol sprays B. Refrigerators The ovary of the flowering plant develop into A. Seed B. Fruit A common characteristic between Bryophytes and A. Produce spores Pteridophytes is that both B. Bear `naked seeds 10 x 2 = (20) SECTION A: [50] SECTION B QUESTION Read the following passage regarding flu and answer the questions that follow Flu, or influenza, is a highly infectious disease caused by viruses. Research has shown that there are different types of flu viruses. When you get flu, your body builds up immunity against a second attack of flu from the same type of virus. However, you are not immune to any other flu virus. Flu injections, which protect one against flu infections, are also not 100% effective because flu viruses are able to mutate, i.e. change their genetic make-up. Therefore, the vaccine against flu must be adapted continuously. The flu virus strains usually differ only slightly from one year to the next. Sometimes a new viral strain develops that is different from the previous forms, so that existing vaccines are not effective against it. These viruses usually cause worldwide pandemics Why is flu considered to be a highly infectious disease? (2) Why is the flu injection not 100% effective against flu? (2) According to the passage `your body builds up immunity against a second attack of flu`. How can a person have repeated bouts of flu? (2) Why can flu NOT be treated with antibiotics? (1)

5 Why does a doctor still prescribe antibiotics for a flu infection? (2) Would you say that the infection caused by the Ebola virus is pandemic? (1) Give a reason for your answer in question number (2) (12) 2.2 Study the diagram which show pictures of a hydra and a planarian below and answer the questions that follow Which animal is a: i. hydra and which is a ii. Planarian? (2) Which distinctive features enable you to identify each animal? (2) Match these animals to each of the following descriptions: i. tubular body, radial symmetry (1) ii. leaf-like and bilateral symmetry (1) iii. three germ layers, organ level of organisation (1) iv. triploblastic acoelomate (1) v. diploblastic sting cells. (1) Which animal is the in a phylum that evolved more recently? (1) List two advances seen in the body structure to support your answer in question (2) Why do you think do many aquatic animals have radial symmetry? (3) (15) 2.3 Study the diagrams below showing the structures of two flowers as well as a pine cone. The magnification of each flower is indicated in brackets.

6 Label parts D, E and F. (3) Which flower A or B is probably pollinated by wind? (1) Give two observable reasons for your answer in question (2) Which flower (A or B) is larger? (1) Identify the plant groups to which flower A and the pine cone belong. (2) State one way in which the seeds of the groups named in question differ. (2) Explain how the dependency on water for reproduction is reduced in the group represented by the pine cone. (2) (13) QUESTION 2 {40} QUESTION The graph below shows the averages of carbon dioxide concentration in the atmosphere since January 2009, as measure at the Mauna Loa Observatory in Hawaii What was the carbon dioxide concentration in the atmosphere in July 2011? (2) Describe how deforestation can lead to increase in carbon dioxide concentration in the atmosphere. (2) Mention ONE human activity, other than deforestation that might have led to the increase in carbon dioxide concentration as seen in the graph. (1)

7 What is the: i. Dependent and (1) ii. Independent variables in this investigation? (1) Explain how the excess carbon dioxide in the atmosphere can lead to climate change. (5) Mention two ways in which humans can reduce the amount of carbon dioxide released into the atmosphere. (2) (14) 3.2 The graph below shows the changes in the levels of CFCs (CFC-11 and CFC-12) and HCFC-22 (which is used as a substitute for CFC) over time. Read the passage and study the graph so that you can answer the questions that follow. In 1987, many countries agreed to a global treaty called the United Nations Montreal Protocol on Substances that Deplete Ozone. This Protocol is aimed to reduce and eventually stop the use of ozone depleting substances worldwide. The protocol came into force in Countries are allowed to use hydrochlorofluorocarbons (HCFCs) as a substitute for CFCs for a while because they are less desctuctive than CFCs. However HCFCs also have to be phased out by How did the levels of CFCs change from 1950 to 1980? (3) How did the levels of CFCs changed since the implementation of the Montreal Protocol in 1989? (3) What has happened with the levels of HCFCs since 1990? (1) Give a reason for your answer in question (1) When is it predicted that the levels of CFC-11 will decrease to the level it was in 1980? (1) Explain, why you think that the Montreal Protocol has been a success to date. (2) How can the experience of the Montreal Protocol help us to solve other global environmental problems such as climate change? (2) (13) 3.3 Despite a great increase in the demand for food, only 7% more land is now used for farming. One of the reasons for this is increase productivity, that is a higher yield per hectare, due to GMOs as well as the

8 8 use of chemicals. In the last 30 years, people have become more aware of the use of chemicals in farming. Some people are concerned about the effects of these on their health and choose to buy organic grown produce. Farmers who use organic methods to produce food do not use chemicals on their crops Give one reason for an increase in the demand for food over the years. (1) State ONE way in which the use of each of the following helps increase productivity: i. Pesticides (1) ii. Fertilisers (1) Describe how the use of pesticides could destroy food chains. (2) Explain why GMOs can be considered to be a threat to food security. (3) Describe how fertilisers cause eutrophication when they are washed into rivers. (5) (13) QUESTION 3 (40) SECTION B {80} SECTION C QUESTION Biodiversity refers to the variety of plant and animal species on Earth. Describe in detail how the different factors causes a reduction in biodiversity and also mention ways in which our biodiversity can be maintained. Content: 17 Synthesis: 03 Total: 20 GRAND TOTAL: [150]