1 1 The classification of giant pandas, Ailuropoda melanoleuca, is debated by many scientists. Photograph A shows a giant panda eating bamboo plants. photograph A Photograph B shows a red panda, Ailurus fulgens, eating bamboo. photograph B 2 Photograph C shows a polar bear, Ursus maritimus, eating fish. photograph C DNA can also be used to classify species. Molecular biologists compared the DNA base sequences of eight species from the same vertebrate group. They used the differences to draw a classification diagram. The diagram shows the classification diagram for these eight species. The shorter the horizontal distance from two species to the branching point that they share, the more similar their DNA sequences are and the more closely the two species are related. The scale on the diagram shows the time at which the molecular biologists estimate that each branching point occurred. red panda ferret giant panda polar bear wolf tiger human mouse 100 80 60 40 million years ago 20 0 3 Morphology can also be used to classify species. Some scientists think that morphology suggests that the giant panda is more closely related to the red panda than it is to the polar bear. (a) (i) Discuss the evidence for and against the giant panda being more closely related to the red panda than it is to the polar bear. Use the information in photographs A, B and C and the diagram in your answer. ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ [5] (ii) State one other type of evidence that is used to classify species. ................................................................................................................................ [1] [Total: 6] 4 2 Baker’s yeast, Saccharomyces cerevisiae, is a single-celled organism that is classified in the kingdom Fungi. The diagram is a drawing of a section through a yeast cell. H A G B F C E D 1 μm The table shows some cell functions. Complete the table by naming the cell structure responsible for each cell function and give the letter that identifies each cell structure in the diagram. cell function cell structure letter from diagram storage of genes aerobic respiration amino acids are assembled to make protein [3] [Total: 3] 5 3 Chloride ions move along the pancreatic duct. CFTR proteins in the cells lining the pancreatic duct move chloride ions out of the cells into the duct. The diagram shows a cell from the lining of the pancreatic duct showing the location and activity of CFTR proteins. The movement of chloride ions into the pancreatic duct causes water to move from the cells into the duct to help the flow of liquid in the duct. Explain how water moves from the cell shown in the diagram into the pancreatic duct. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [3] [Total: 3] 6 4 The table shows some of the nutrients found in human milk, the elements that make up the nutrients, the enzymes that digest them and the products of digestion. Complete the table. nutrient elements enzyme products of digestion protein fat lactose (milk sugar) C, H, O galactose and glucose (simple sugars) [4] [Total: 4] 5 Yeast cells make the enzyme sucrase. Sucrase catalyses the breakdown of sucrose to glucose and fructose. Enzymes are made of protein. Explain how the shape of a sucrase molecule is related to its function. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [2] [Total: 2] 7 6 Researchers have devised a process of artificial photosynthesis. They use gold nanoparticles as a catalyst to utilise green light to convert carbon dioxide to fuels, such as propane. Suggest the advantages to the environment of using artificial photosynthesis on a large scale. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [2] [Total: 2] 7 The pancreas is an organ that has roles in the digestive and hormonal systems of humans. The diagram shows part of the alimentary canal and some of the associated organs. State the names of organs J, K and L. J ................................................................................................................................................ K ............................................................................................................................................... L ............................................................................................................................................... [3] [Total: 3] 8 8 One purpose of seed banks is to reintroduce plant species into their natural environment. A survey was done to find out why some reintroduction programmes are not successful. The graph shows the results of the survey. 40 35 30 percentage of species that were not successfully reintroduced 25 20 15 10 5 0 reason unknown wrong habitat changing seeds did seedlings too few habitat not too young individuals germinate wrong season reasons why reintroductions failed Some reintroduction programmes failed because the seedlings were too young. Young seedlings only have a few small roots. Explain why it would be important to reintroduce plants with many large roots. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [4] [Total: 4] 9 9 The diagram shows the double circulation of a mammal. The arrows indicate the movement of oxygen and carbon dioxide in and out of the blood. Explain the advantages of a double circulation. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. [4] [Total: 4]
