As Biology (7401/1) Paper 1 Specimen 2014 Already Passed

06 . 1) Figure 7 represents a capillary surrounded by tissue fluid. The values of the hydrostatic pressure are shown. Use the information in Figure 7 to explain how tissue fluid is formed. [2 marks] {Ans: 1. (Overall) outward pressure of 3.2 kPa; 2. Forces small molecules out of capillary;}04 . 2) Scientists determined that a sample of DNA contained 18% adenine. What were the percentages of thymine and guanine in this sample of DNA? [2 marks] {Ans: 1. Thymine 18(%); 2. Guanine 32(%);}08 . 1) A group of students carried out an investigation to find the water potential of potato tissue. The students were each given a potato and 50 cm3 of a 1.0 mol dm-3 solution of sucrose. They used the 1.0 mol dm-3 solution of sucrose to make a series of different concentrations. They cut and weighed discs of potato tissue and left them in the sucrose solutions for a set time. They then removed the discs of potato tissue and reweighed them. Table 3 shows how one student presented his processed results. Explain why the data in Table 3 are described as processed results. [1 mark] {Ans: Calculations made (from raw data)/raw data