Hilton College Grade 10 Life Sciences Exam Paper 1 November 2023 PDF

Page 1 of 23 HILTON COLLEGE EXAMINATIONS NOVEMBER 2023...

Page 1 of 23 HILTON COLLEGE EXAMINATIONS NOVEMBER 2023 GRADE 10 - LIFE SCIENCES: PAPER 1 LAUNDRY NUMBER: Time: 2 hours Total 150 Examiner: Mr H Steenkamp Moderators: Mrs T Mackenzie, Mr J Robey & Mr Shuttleworth PLEASE READ THE FOLLOWING INSTRUCTIONS CAREFULLY 1. Ensure your laundry number is written in the space provided. 2. This paper consists of 6 questions on 23 pages. 3. Page 23 is a blank page. Use this page if you run out of space on a question. 4. Please check that your paper is complete. 5. Ensure you read all the questions carefully. 6. Answer the questions in the space provided. 7. It is in your own interest to work neatly and legibly. ___________________________________________________________________________ FOR EXAMINATION USE ONLY Question 1 2 3 4 5 6 Total Total  Page 2 of 23 SECTION A QUESTION 1 1.1 Answer the following question by choosing the most correct answer from those available. Write the LETTER only, of the correct answer in the space provided. Question 1.1.1 1.1.2 1.1.3 1.1.4 1.1.5 1.1.6 1.1.7 1.1.8 Answer Question 1.1.9 1.1.10 1.1.11 1.1.12 1.1.13 1.1.14 1.1.15 1.1.16 Answer (16) 1.1.1 Which of the following correctly shows the levels of organisation in an organism in order of size from the smallest to the largest? A Organelle, cell, organ, tissue, organ system. B Organelle, cell, tissue, organ, organ system. C Cell, organelle, tissue, organ, organ system. D Cell, tissue, organelle, organ, organ system. 1.1.2 Which of the following statements relating to respiration is not correct? A Respiration produces ATP. B Respiration involves the breaking of bonds within biological molecules. C Respiration occurs in animals but not in plants. D Respiration releases energy in the form of heat. 1.1.3 Earthworms are known as detritivores: they break down dead plant and animal material in the soil. Which statement best describes how oxygen from the soil moves into the body fluids of the earthworm to be used for respiration. A By diffusion down a concentration gradient. B By diffusion from a low concentration to a high concentration. C By osmosis down the concentration gradient. D By active transport from a low concentration to a high concentration.  Page 3 of 23 1.1.4 Which of these is balanced chemical symbol equation for aerobic respiration? A C6H12O6 + 6O2 → 6CO2 B C6H12O6 → 2C2H5OH + 2CO2 C C6H12O6 + 6CO2 → 6O2 + 6H2O D C6H12O6 + 6O2 → 6CO2 + 6H2O 1.1.5 The diagram shows the human thorax. Which of the following are structures Q and R? Q R A bronchiole trachea B bronchus trachea C trachea bronchus D trachea bronchiole 1.1.6 Which of the following best describes what an enzyme is? A A catalyst that speeds up reactions in cells, being used up in the process. B A protein that speeds up reactions in cells, being used up in the process. C A carbohydrate that functions as a biological catalyst. D A protein that functions as a biological catalyst.  Page 4 of 23 1.1.7 The drawing shows a food test being carried out in a laboratory. Which food test is being shown and which food group is being tested for? A Biuret test for proteins. B DCIP test for Vitamin C. C Benedicts test for sugars. D Emulsion test for fats. 1.1.8 What can be said is true of all enzymes.  Page 5 of 23 1.1.9 The image below represents a chemical reaction. Which of the following best represents the enzyme responsible for catalysing this reaction. 1.1.10 The diagram below shows a single-celled organism called Euglena. Which labelled structures would also be found in an animal cell. A cell membrane, chloroplast, nucleus B chloroplast, cytoplasm, nucleus C cell membrane, cytoplasm, nucleus D cell membrane, cytoplasm, large permanent vacuole 1.1.11 Which part of a cell makes glucose? A cell membrane C nucleus B chloroplast D vacuole  Page 6 of 23 1.1.12 The figure below shows four stages of mitosis, labelled P, Q, R and S. Which is the correct order for these stages? A Q→R→S→P C R→Q→S→P B R→S→Q→P D Q→S→R→P 1.1.13 The stage of mitosis labelled S in the figure in Question 1.1.12 is A anaphase C telophase B prophase D metaphase 1.1.14 Which shows the changes in appearance of a plant cell as it remains in a concentrated sugar solution for 30 minutes.  Page 7 of 23 1.1.15 Starch is digested by amylase in the mouth, but it is not digested in the stomach. What is the reason for this? A All starch digestion is completed in the mouth. B The pH in the stomach is not suitable for amylase to work. C The starch does not stay in the stomach long enough to be digested. D The temperature in the stomach is not suitable for the amylase to work. 1.1.16 Some statements about mitosis are listed below. 1 Cells divide and produce new cells to repair damaged tissues. 2 Chromosomes are duplicated, and the cell separates to form gametes. 3 Chromosomes are duplicated, and the cell separates to form identical cells. 4 Mitosis is used in asexual reproduction. Which statements are correct? A 1, 2 and 3 C 2 and 4 B 1, 3 and 4 D 3 and 4 only (16) 1.2 The image below shows four specialised cells. Each cell is represented by a letter. A – D. Use this diagram to answer questions on the next page.  Page 8 of 23 Identify one letter, A – D, that corresponds to a cell that is described in each of the following statements. Each letter may be used once, more than once, or not at all. 1.2.1 This is a plant cell ____________________________________________________ (1) 1.2.2 This cell contains digestive enzymes _____________________________________ (1) 1.2.3 This cell is motile (moves around) _______________________________________ (1) 1.2.4 This cell is involved in co-ordination of the body’s activities __________________ (1) 1.3 The diagram shows an animal cell. 1.3.1 Provide names for the structures labelled W – Z. W _________________________ X ________________________ Y __________________________ Z ________________________ (4) 1.3.2 Name the structure where respiration takes place. __________________________________________________________________ (1) Using some of the words provided, complete the following sentence about respiration. glucose, chemical, protein, cell, muscle, temperature, nerve 1.3.3 Respiration releases energy from ____________________. The energy release can be used in life processes such as ____________________ reactions, ____________________ contraction and maintaining a constant body ____________________. (4)  Page 9 of 23 1.4 The diagram below shows a plant cell drawn to scale. 1.4.1 Calculate how many times longer the cell length is than the chloroplast length. Show all calculations. _____________________________________________________________________ __________________________________________________________________ (2) 1.4.2 State three ways in which an animal cell would be different to the cell shown above. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3) 1.5 Complete the table with a (√) or a (X) to show the products and reactants of aerobic respiration in animals. (6)  Page 10 of 23 QUESTION 2 A student wanted to investigate the transport of water across a partially permeable membrane. The diagram shows how the student prepared the beaker at the start of the investigation. 2.1.1 On the diagram show what the student would observe after 15 minutes. (2) The student carried out a further investigation into the effect of osmosis on plant tissue. They cut a potato into cubes and recorded the change in mass over a 30 minute period. The graph shows the results the student obtained from one cube of potato. The cubes where in a water bath at room temperature.  Page 11 of 23 2.1.2 Describe and explain the trend shown on the graph. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (6) The student repeated the investigation but with the beaker placed in a water bath at 30 oC. 2.1.3 Draw a second line on the graph to show the trend expected from these results. (2) 2.1.4 Explain your line drawn for Question 2.1.3. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) The student then wrote down the following statement about osmosis. “The active movement of molecules through a membrane from a region of low concentration to a region of high concentration.” 2.1.5 Using your knowledge of osmosis, suggest what is wrong with this statement. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (4)  Page 12 of 23 QUESTION 3 3.1.1 State the purpose of replication of DNA. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) The diagrams below show two models of DNA replication. 3.1.2 State which diagram A or B, is correct. Explain your choice. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3) DNA is used to make a copy of RNA called mRNA. It does this by matching up with complementary nitrogenous base pairs. 3.1.3 Complete the table below with the base sequence of the RNA strand. (2)  Page 13 of 23 The diagram shows the structure of one strand of DNA. 3.1.4 Name the molecules labelled W, X, Y and Z as specifically as possible. W _________________________ X ________________________ Y __________________________ Z ________________________ (4) The diagram below shows chromosomes at different stages of the cell cycle. 3.2.1 Of the cells in mitosis, place the stages in the correct order by completing the table below. The first stage has been done for you. Continue from there. Stages of Mitosis Letter 1 E 2 3 4 (3)  Page 14 of 23 Scientists investigated the effect of mitotic inhibitor drugs which prevents microtubule formation. One such drug is Vincristine; a chemotherapy drug that binds irreversibly to microtubules and spindle proteins and interferes with the formation of mitotic spindle fibres. The scientists found that Vincristine was effective at halting the cell cycle in both healthy and cancerous cells. 3.2.2 Explain why preventing the formation of spindle fibres stopped the cell cycle. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3) 3.2.3 Explain why Vincristine can be used as a treatment for cancer even though it affects some healthy cells. _____________________________________________________________________ __________________________________________________________________ (2) The diagram below shows a structure in a cell undergoing mitosis. 3.3.1 Identify structure P? __________________________________________________________________ (1) 3.3.2 Describe the role of structure P during mitosis. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) 3.3.3 Identify the stage of mitosis that the chromosome could be in and give a reason for your answer. ____________________________________________________________________ ____________________________________________________________________ __________________________________________________________________ (2)  Page 15 of 23 QUESTION 4 The diagram below shows an alveolus. 4.1.1 Explain one feature visible in the diagram which allows efficient gas exchange. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) 4.1.2 Using an ‘X’ on the diagram above, indicate where the oxygen content of the blood is the highest. (1) 4.1.3 On the diagram above, label (i) a squamous epithelium cell and (ii) a cuboidal epithelium cell. (2) 4.1.4 Explain how the squamous epithelium tissue is suited to the function it performs in an alveolus. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3)  Page 16 of 23 The estimated surface area of the lung system of a new-born baby is 4.2 m2; this is around one twentieth of the overall surface area of a typical adult’s lungs. 4.1.5 Calculate the overall surface area of a typical adult’s lungs. Show all calculations. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3) Gas exchange occurs at the alveoli 4.1.6 Describe how oxygen molecules move from the alveoli into the blood. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (4) 4.1.7 Name the gas which moves from the capillary into the alveoli before being exhaled from the body. __________________________________________________________________ (1) Emphysema is a disease of the lungs which results in damage to the alveoli leaving fewer, large alveoli rather than many small alveoli. 4.1.8 Suggest the effect this would have on the surface area of the lungs. _____________________________________________________________________ __________________________________________________________________ (1) 4.1.9 How would emphysema effect a person’s level of physical activity. Explain your answer. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3)  Page 17 of 23 QUESTION 5 The diagram shows a leaf palisade mesophyll cell. 5.1.1 Name and describe one function of the parts labelled A, B, and C. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (6) The diagram below shows the cross section of a leaf. Structure Y represents a vascular bundle.  Page 18 of 23 5.2.1 Identify two types of tissue found in structure Y. _____________________________________________________________________ __________________________________________________________________ (2) 5.2.2 Describe the function of each type of tissue identified in Question 5.2.1. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) Layer X and Z in the above diagram form the outer boundaries of the leaf. 5.2.3 Name these outer boundaries. __________________________________________________________________ (1) 5.2.4 What would you expect to find on layer X and what is the function thereof? _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) 5.2.5 State one visible difference between layer X and Z. _____________________________________________________________________ __________________________________________________________________ (1) The cells in layer X are transparent. 5.2.6 Explain the importance of this to the plant. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2)  Page 19 of 23 QUESTION 6 The diagram below shows the mechanism of enzyme action. 6.1 State the name given to molecule X and location Y in a chemical reaction. _____________________________________________________________________ __________________________________________________________________ (2) Enzyme activity is affected by environmental factors such as temperature. Sometimes environmental extremes lead to denaturing of enzymes. 6.2.1 Name another factor, other than temperature which may result in denaturing of enzymes. __________________________________________________________________ (1) 6.2.2 Describe what is meant by ‘denaturing’ of enzymes. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3)  Page 20 of 23 The effect of temperature on enzyme activity was investigated. The results are shown below. 6.3.1 State the optimum temperature for the enzyme as shown in the graph. __________________________________________________________________ (1) 6.3.2 State why there is no enzyme activity at 60 oC. __________________________________________________________________ (1) 6.3.3 Would you expect this enzyme activity data to be that of a human? Explain your answer. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (3)  Page 21 of 23 The table below shows some large insoluble molecules, some digestive enzymes and some smaller molecules that are produced during digestion. 6.4.1 Complete the table by writing the names of the missing enzyme and molecules. The first row has been done for you. (5) 6.4.2 List the chemical elements present in fats. __________________________________________________________________ (3) 6.5.1 Predict the colour changes (if any) of the iodine test on the food samples shown below: (5) The cells of animals require cellular energy. 6.5.2 Write a balanced chemical equation for aerobic respiration in animals. __________________________________________________________________ (2)  Page 22 of 23 6.5.3 Identify two different ways in which animals use the energy released by aerobic respiration. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2) In the absence of sufficient oxygen, cells respire anaerobically. 6.5.4 Compare anaerobic respiration in the muscle cell of an animal cell with anaerobic respiration in a yeast cell. Refer to the products of both reactions. _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (4) In animals, prolonged exercise cannot be sustained with anaerobic respiration. 6.5.5 Explain why. _____________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ (2)  Page 23 of 23 ADDITIONAL SPACE (ALL QUESTIONS) REMEMBER TO CLEARLY INDICATE AT THE QUESTION THAT YOU USED THE ADDITIONAL SPACE TO ENSURE THAT ALL ANSWERS ARE MARKED. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________