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. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________

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)

An experiment was conducted to determine how quickly water would move from one area to another through the process of osmosis.Six different concentrations of sucrose were placed in identical containers, with the same volume of solution in each. The containers allowed water to pass through, but nothing else. Containers were placed in equal volumes of water. The containers sat in the solution for 30 minutes. The initial and final masses of the containers were taken, and a percent change in mass was calculated to determine how much water entered the tubing during the 30-minute time period.What is the independent, dependent, and control variable in the experiment?Elimination ToolSelect one answerAIndependent Variable Dependent Variable ControlPercent Change in Mass Concentrations of Sucrose ContainersBIndependent Variable Dependent Variable ControlConcentrations of Sucrose Percent Change in Mass ContainersCIndependent Variable Dependent Variable ControlConcentrations of Sucrose Containers Percent Change in MassDIndependent Variable Dependent Variable ControlContainers Concentrations of Sucrose Percent Change in Mass

The diagram shows a set-up used to demonstrate osmosis. The 15% sugar solution is ........... the 30% sugar solution.

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

An experiment was set up to determine the movement of molecules through a dialysis-tubing bag into water. A dialysis-tubing bag containing 5 percent lactose and 5 percent fructose was placed in a beaker of distilled water, as illustrated in the given figure. After 4 h, fructose is detected in the distilled water outside of the dialysis-tubing bag, but lactose is not.What conclusions can be made about the movement of molecules in this experiment?