Science 103: Practice Exam 2

Transcription

1 Name: Science 103: Practice Exam 2 Do this exam AFTER studying and under exam conditions. Give yourself ONE HOUR to do the exam. Hand in a copy of this paper in the review session. This will be your homework assignment. MULTIPLE CHOICE: 1. During interphase, chromosomes: (A) line up at the cell equator. (B) separate into sister chromatids. (C) coil tightly around histones. (D) replicate. (E) A and C. 2. At the G 1 checkpoint: (A) cytokinesis starts. (B) sister chromatids separate and move to opposite poles of the cell. (C) the decision is made to divide, delay, or enter a resting stage. (D) cancerous cells begin cell division. (E) all of the above. 3. The cell cycle of eukaryotes is controlled: (A) at 3 checkpoints. (B) during S phase. (C) during C phase. (D) during metaphase and telophase. 4. p53 is: (A) a tumor suppressor gene. (B) part of the kinetochore. (C) a structure that forms the spindle fibers. (D) a transmembrane protein. (E) involved in active transport. 5. Gametes: (A) are haploid cells. (B) fuse to form a zygote. (C) are produced by meiosis. (D) all of the above. 6. In prophase I of meiosis: (A) crossing over occurs. (B) chromosomes reach opposite poles of the cell. (C) chromosomes align at the cell equator. (D) the nuclear membrane is reformed. (E) sister chromatids separate. 7. In anaphase I of meiosis: (A) crossing over occurs. (B) the cytoplasm divides. (C) the homologues separate. (D) sister chromatids separate. (E) the centrioles form the spindle fibers. 1

2 8. In metaphase of mitosis: (A) the homologues align at the cell equator. (B) the homolgues separate. (C) chromosomes align at the cell equator. (D) the nuclear membrane breaks down. (E) the chromosomes condense. 9. The structure of chromosomes in all stages of the cell cycle is partly maintained by: (A) covalent bonding between the strands of the double helix. (B) ionic bonding between the strands of the double helix. (C) the centromere. (D) winding of the DNA molecule around a core of proteins. (E) the spindle fibers. 10. Sister chromatids are: (A) only seen in prokaryotes. (B) homologous chromosomes. (C) formed only in meiosis. (D) joined at crossing over. (E) duplicated DNA held together by a centromere. 11. Human nerve cells are: (A) haploid. (B) produced by meiosis. (C) constantly reproducing. (D) diploid. (E) deficient in p In S phase of mitosis the is synthesized. (A) cell wall (B) plasma membrane (C) Golgi complex (D) DNA (E) RNA 13. Alternation of generations refers to: (A) the alternation of egg and sperm. (B) the alternation of a haploid and a diploid generation. (C) the presence of 2 sexes. (D) the dependence of one generation on the next. 14. Genetic variation is ensured by: (A) random fertilization. (B) crossing over during meiosis. (C) independent assortment. (D) all of the above. 15. Trisomy is: (A) one chromosome too few. (B) tetraploidy. (C) a type of cancer. (D) a tumor suppressor gene. (E) one chromosome too many. 2

3 16. A benign tumor is: (A) composed of mobile cells that seed new tumors in secondary tissues. (B) malignant. (C) encapsulated and non-invasive. (D) a childhood cancer. 17. The end product of glycolysis is: (A) acetyl-co A. (B) carbon dioxide and water. (C) pyruvate. (D) glucose. (E) oxaloacetate. 18. The Krebs cycle occurs in the: (A) cytoplasm. (B) stroma. (C) matrix. (D) thylakoid membrane. (E) inner mitochondrial membrane. 19. are responsible for the formation of a cleavage furrow in mitosis and meiosis. (A) Microtubules (B) Microfilaments (C) Intermediate filaments (D) Spindle fibers (E) Tubulin subunits 20. Which of the following are examples of electron carriers that are used in respiration? (A) NADH. (B) NADPH. (C) FADH 2. (D) A and C. (E) all of the above. 21. The final electron acceptor in aerobic respiration is: (A) water. (B) oxygen. (C) NAD +. (D) FADH 2. (E) glucose. 22. In aerobic respiration carbon dioxide is produced in: (A) gycolysis. (B) Krebs cycle. (C) acetyl-coa production. (D) the electron transport chain. 23. The function of glycolysis is to: (A) produce NADPH and ATP. (B) the starting material for further energy extraction by oxidation. (C) produce glucose. (D) produce NADH and FADH 2. (E) make 36 ATP from one glucose molecule. 3

4 24. The net energetic products of Krebs cycle are: (A) 2 ATP and 2 NADH. (B) 2 ATP, 6 NADH, and 2 FADH 2. (C) 2 NADH. (D) 36 ATP. (E) one molecule of glucose and 9 ATP. 25. The H + are pumped from to in the electron transport chain of respiration: (A) stroma to thylakoid space. (B) thylakoid space to stroma. (C) matrix to intermembrane space. (D) intermembrane space to matrix. (E) cytoplasm to intermembrane space. 26. In respiration, NADH activates proton pumps: (A) 1. (B) 2. (C) 3. (D) 4. (E) ATP net, rather than 34 ATP net, are made by the electron transport chain of respiration because: (A) the NADH made by glycolysis has to be transported into the mitochondrial matrix. (B) the NADH made by glycolysis has to be transported into the cytoplasm. (C) the NADH made by Krebs cycle has to be transported into the mitochondrial matrix.. (D) the NADH made by Krebs cycle has to be transported into the cytoplasm. 28. The most efficient process (in the following list) of cellular respiration is: (A) glycolysis. (B) acetyl-coa production. (C) Krebs cycle. (D) Calvin cycle. (E) light reactions. 29. The prokaryotic cell cycle consists of: (A) interphase with 3 checkpoints. (B) DNA replication. (C) binary fission. (D) B and C. (E) all of the above. 30. Mitosis can be defined as: (A) nuclear division in somatic cells. (B) nuclear division in germ cells. (C) binary fission. (D) cytoplasmic division in somatic cells. (E) DNA replication. 31. A cell plate is formed in: (A) binary fission of prokaryotic cells. (B) cytokinesis in animal cells. (C) cytokinesis in plant cells. (D) metaphase of mitosis. 4

5 32. Programmed cell death: (A) does not occur in cancer cells. (B) is important for fetal development. (C) occurs after approximately 50 divisions in human cells. (D) all of the above. 33. Cancer occurs in humans less frequently than expected because: (A) humans are rarely exposed to carcinogens. (B) human DNA rarely mutates. (C) p53 detects cancers and signals the cell accordingly. (D) ATP checks the cell at certain points in the cell cycle. 34. The pairing of homologues in prophase I of meiosis is called: (A) crossing over. (B) synapsis. (C) gametogenesis. (D) independent assortment. (E) kinetochore. 35. Ploidy is: (A) breakdown of the nucleus in cell division. (B) an attachment between homologues that have crossed over. (C) detachment of the chromosomes from the kinetochore microtubules at the end of mitosis. (D) the number of sets of chromosomes possessed by a cell. 36. Mitosis and meiosis differ in: (A) the number of cell divisions that occurs. (B) the final ploidy of the daughter cells. (C) the number of daughter cells produced. (D) the composition of the spindle fibers. (E) A, B, and C. (Multiple choice = 36 points) 5

6 The rest of the answers go on the exam. 37. The diagram shows a cell that has 6 chromosomes and is in prophase of mitosis. Draw the cell in the remaining stages of mitosis and all the stages of meiosis. Make sure you label your diagrams. (In the exam you will be given a subset of the stages, so don t worry if this takes longer than the allotted time). Practice drawing these from memory you will have to do it in the exam. (22 points) 6