A student puts five raisins each in two beakers A and B. Beaker A contained 50 mL of distilled water and beaker B had 50 mL of saturated sugar solution. After some time the student would observe that

A student dissolved 5 g of sugar in 100 mL of distilled water in beaker A. She dissolved100 g of sugar in100 mL of distilled water in beaker B. Then she dropped a few raisins ofequal weight in each beaker. After two hours she found the raisins in A swollen and thosein B shrunken. The inference drawn is thata) sugar concentration of raisins is lower than that of solution A and higher than thatof solution B.b) sugar concentration of raisins is higher than that of solution A and lower than thatof solution B.c) in B the cell membrane of raisins was damaged.d) in A the permeability of the cell membrane of raisins to water was enhanced

A student adds two teaspoons of sugar to two glasses, each containing the same amounts of water.How will the student then make the solution in Glass P less concentrated than the solution in Glass Q?ResponsesAdd more water to Glass P.Add more water to Glass P.Add the same amount of water to both Glasses P and Q.Add the same amount of water to both Glasses P and Q.Remove some water from Glass P.Remove some water from Glass P.Remove the same amount water from both Glasses P and QRemove the same amount water from both Glasses P and Q

Some students set up an experiment using osmosis to find the concentration of sucrose solution in potato cell sap. They used discs of potato cut to the same size and weighing approximately 10 gms. The discs were put into each of five beakers.2. (a) (i) After two hours they reweighed the discs after carefully blotting them first. Why did the students blot the potato before weighing it? ______________________________________________________________ ______________________________________________________________ (1) (ii) Their results are shown in the table below.Beaker 1 Beaker 2 Beaker 3 Beaker 4 Beaker 5 Final mass in g 13.0 12.2 9.0 7.9 7.3 Initial mass in g 10.0 10.6 10.0 10.1 10.4 Page 3 of 16It improves the rate of diffusion as there is less distance for the exchange of gases to occur. Another is that there will be no blockages in the capillaries as there are not lots of blood cells that can cause blockages.It also helps in maintaining blood pressure The students calculated the % gain or loss in mass of potato. Complete this table of results for Beakers 2, 4 and 5.Beaker 1 Beaker 2 Beaker 3 Beaker 4 Beaker 5 13 – 10.0 = 3.09.0 – 10.0 = –1.0 = –10%Gain in mass = 30%Loss in mass = 10%(3) (b) (i) Draw a graph of % Gain or Loss in mass against sucrose concentration.(3) Page 4 of 16(ii) Use the graph to find the concentration of potato cell sap. Concentration of cell sap = _____________________ % sucrose solution (1) (iii) Explain in terms of osmosis how you chose this value. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ (2) (Total 10 marks) (a) Some scientists investigated the rates of absorption of different sugars by the small intestine. In one experiment they used a piece of normal intestine. In a second experiment they used a piece of intestine poisoned by cyanide. Cyanide is poisonous because it prevents respiration. The results are shown in the table.Relative rates of absorption SugarNormal intestine Intestine poisoned by cyanide Glucose1.000.33 Galactose1.100.53 Xylose0.300.31 Arabinose0.290.29 3. (i) Name two sugars from the table which can be absorbed by active transport. 1. ____________________________________________________________ 2. ____________________________________________________________ (1) Page 5 of 16(ii) Use evidence from the table to explain why you chose these sugars. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ (3) (b) All of the sugars named in the table can be absorbed by diffusion. Explain how information from the table provides evidence for this. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (Total 6 marks)

ome students set up this experiment to investigate osmosis. They filled two pieces of dialysis [visking] tubing with different liquids and left them both in a beaker of 5% sucrose solution for an hour.9.(a) Describe and explain the likely results after one hour. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (6) Page 17 of 18It is important as it contains half the genetic material which will join with the other half ofthe genetic material in the egg to form a full set of chromosomes. the chromosomes is what will determine the characteristics of the offspring(b) Describe two examples where osmosis is used in living things. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

A solution of ‘THANDA SHARBAT’ has 15% sugar. Another solution has 5% sugar. How many liters’ of the second solution must be added to the 20L of first solution to make a solution of 10 % sugar?