Gr-10 Practice Questions Biology Ch-4 3(a) Dialysis tubing is an artificial membrane, which is similar to the lining of the intestine. A student investigated the diffusion of glucose through dialysis tubing by using the apparatus shown in Fig. 3.1. Fig. 3.1 The student took samples of the water outside the dialysis tubing at 5 minute intervals and tested the samples with Benedict’s solution. The results are shown in Table 3.1. Table 3.1 (i) Describe and explain the results shown in Table 3.1. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................... ........................................................................................................................................................................... ...................................................................................................................................................................... [3] (ii) The student repeated the investigation with a higher concentration of glucose in the dialysis tubing. Predict the results that the student would observe. ........................................................................................................................................................................... ...................................................................................................................................................................... [1] 2 Fig. 2.1 shows the apparatus used to find the energy in a groundnut. Results of the experiment are shown in Table 2.1. Fig. 2.1 Table 2.1 (a) Describe how the apparatus could be used to obtain the data shown in Table 2.1. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................[5] (b) The energy released by a groundnut was calculated using the equation shown below. energy = volume of water × increase in temperature × 4.2 Calculate the energy released by a groundnut of mass 0.4 g. Show your working. energy = ............... J [2] (c) Fig. 2.2 shows a graph of the relationship between mass of groundnut and the energy it contains. The graph is incomplete. Fig. 2.2 (i) Complete the graph, by adding the missing energy value, calculated in (b), drawing a line through the points and labelling the axes. [3] (ii) Describe the trend shown by the graph. ........................................................................................................................................................................... .......................................................................................................................................................................[1] (d) (i) The experimental results show that a groundnut of mass 0.5 g contains 3045 J energy. Calculate the energy released from 100 g of these groundnuts. energy in 100 g = ............... J [1] ------------------------------------------------------------------------------------------------------------------------------------------- 3 (b) Glucose in the blood is absorbed by liver cells and muscle cells. These cells convert glucose to glycogen for storage. Explain why glucose needs to be converted to glycogen for storage rather than remaining dissolved in the blood. ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................[2] 0610/33/MJ/13 9 (b) Describe how you could test for the presence of reducing sugars. State what you would observe if the result was positive. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................[3] 0610/21/O/N/13 5 Malnutrition is caused by some imbalance in the diet or lifestyle. (a) This is a list of some effects of malnutrition. Constipation coronary heart disease obesity starvation toothdecay Use the list to complete Table 5.1. Table 5.1 5 (c) Milk is sometimes described as the ‘complete food’. Milk is made up of 84% water and 16% milk solids. Fig. 5.1 shows the percentage composition of milk solids. Fig. 5.1 Use the data in Fig. 5.1 to calculate the percentage of protein present in the milk solids. Show your working. % protein in the milk solids............................................................................................................................ [2] - (a) Marmots and lynx are mammals that can live in a variety of environments. The percentage of fat in the bodies of these two species was measured. Measurements were taken from marmots and lynx living in Alaska and in Virginia. Alaska is a cold environment and Virginia is a warm environment. The results are shown in Table 1.1. Table 1.1 (i) Complete Table 1.1 by calculating the difference in the percentage of fat in the body for the lynx. Write your answer in Table 1.1. [1] (ii) Describe the results shown in Table 1.1. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ...................................................................................................................................................................... [2] (iii) Explain the difference in the percentage of fat in the body between the mammals living in Alaska and Virginia. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ...................................................................................................................................................................... Gr-10 Practice Questions Biology Ch-5 6 A student investigated the effect of changing pH on the rate of reaction of a digestive enzyme. (a) Define the term enzyme. ............................................................................................................................................................... ............................................................................................................................................................... ..........................................................................................................................................................[2] Table 7.1 shows the results of this investigation. Table 7.1 (b) Plot the results as a line graph on Fig. 7.1. [3] Fig. 7.1 pH (c) Suggest where in the human digestive system this enzyme would have been most active. ...................................................................................................................................................................[1] (d) The investigation at pH 3 was repeated but the enzyme was boiled before its use. Suggest how and why the results would have been different. ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................[2] [Total: 8] 0610/02/M/J/07 3 Catalase is an enzyme found in plant and animal cells. It has the function of breaking down hydrogen peroxide, a toxic waste product of metabolic processes. (a) (i) State the term used to describe the removal of waste products of metabolism. .......................................................................................................................................................................[1] (ii) Define the term enzyme. ........................................................................................................................................................................... .......................................................................................................................................................................[2] An investigation was carried out to study the effect of pH on catalase, using pieces of potato as a source of the enzyme. Oxygen is formed when catalase breaks down hydrogen peroxide, as shown in the equation. The rate of reaction can be found by measuring how long it takes for 10 cm3 oxygen to be collected. (b) (i) State the independent (input) variable in this investigation. .......................................................................................................................................................................[1] (ii) Suggest two factors that would need to be kept constant in this investigation. 1. ....................................................................................................................................................................... 2. ...................................................................................................................................................................[2] Table 3.1 shows the results of the investigation, but it is incomplete. Table 3.1 (c) Calculate the rate of oxygen production at pH 8. Show your working. Write your answer in Table 3.1 (d) Complete the graph by plotting the rate of oxygen production against pH. (e) (i) Using data from the graph, describe the changes in the reaction rate between pH 4 and pH 8. ........................................................................................................................................................................... ........................................................................................................................................................................... .......................................................................................................................................................................[2] (ii) Explain the change in the reaction rate between pH 6 and pH 8. ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ........................................................................................................................................................................... ......................................................................................................................................................................[3] [Total: 17]
