Tiêu đề Feb-Mar_2025_9700_12_QP - Crack A Level.pdf ✅

2 © UCLES 2025 9700/12/F/M/25 1 In an electron micrograph, the length of a mitochondrion is measured as 17.1 cm. The magnification of the electron micrograph is 38 000. What is the actual length of the mitochondrion? A 0.22 m B 0.45 m C 2.22 m D 4.50 m 2 There is a theory that mitochondria and chloroplasts were originally free-living prokaryotes. It is thought that millions of years ago these free-living prokaryotes were taken into larger cells by endocytosis where, instead of being digested, they became functional organelles. Which features of mitochondria and chloroplasts support this theory? 1 Mitochondria and chloroplasts are surrounded by double membranes. 2 Mitochondria and chloroplasts have small, circular DNA. 3 Mitochondria and chloroplasts synthesise proteins. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 3 Which row correctly describes a function of each cell structure? lysosome mitochondrion smooth endoplasmic reticulum A digestion of unwanted structures abundant in sites of active transport processing of proteins B digestion of unwanted structures ATP synthesis lipid production C spherical sacs containing hydrolytic enzymes abundant in sites of active transport lipid production D spherical sacs containing hydrolytic enzymes ATP synthesis processing of proteins 4 Which cell components are present in typical prokaryotic cells? cell wall 80S ribosomes A key B = present C = not present D
3 © UCLES 2025 9700/12/F/M/25 [Turn over 5 X-ray analysis of fossilised cells found in rocks in central India dating back 1.6 billion years has revealed several features. 1 The cells are up to 145 m long. 2 The cells are joined end to end to form filaments. 3 The cells contain some internal cell structures. 4 The cells are surrounded by a cell wall. Which two features, when taken together, provide most support for the conclusion that the cells are plant cells? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 6 The electron micrograph shows an organelle found in some cells of many multicellular organisms. Which row shows structures that are expected to be present in cells that contain this organelle? cell wall centrioles plasmodesmata A key B = expected to be present C = not expected to be present D 7 What could take place during a hydrolysis reaction? 1 A glycosidic bond is broken. 2 A molecule of water is produced. 3 A sucrose molecule is split into fructose and glucose. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only