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AP Biology Free-Response Question Preparation Directions: Answer all questions on separate pieces of paper. Then use the scoring guides on the College Board website (http://apcentral.collegeboard.com/apc/members/exam/exam_information /219291.html ) to grade your answer. Each response/scoring of response is worth up to 6 points. Answering and then scoring at least two of the free-response questions are required. Answering all four free-response questions will enable you to earn up to 24 out of 12 points or 12 points extra credit in the test category of your grade. Work independently on the writing of your free-response. Also try following the timing guidelines (90 minutes to answer all four questions below). Directions on writing your response from the College Board: Answers must be in essay form. Outline form is not acceptable. Labeled diagrams may be used to supplement discussion, but in no case will a diagram alone suffice. It is important that you read each question completely before you begin to write. Write all your answers on the pages following the questions in the goldenrod booklet. Questions 1 and 2 are 2011 Free-Response Form B questions which may be found at http://apcentral.collegeboard.com/apc/public/repository/ap11_frq_biology_formb.pdf. The scoring guide for question one is found at http://apcentral.collegeboard.com/apc/public/repository/ap11_biology_form_b_scoring_guidelines.pdf . 1. The cell cycle is fundamental to the reproduction of eukaryotic cells. (a) Describe the phases of the cell cycle. (b) Explain the role of THREE of the following in mitosis or cytokinesis. Kinetochores Microtubules Motor proteins Actin filaments (c) Describe how the cell cycle is regulated and discuss ONE consequence of abnormal regulation. 2. Ecological succession describes the pattern of changes in communities over time. The graph below shows changes in plant diversity following the abandonment of an agricultural field in a temperate biome. (a) Discuss the differences in plant diversity shown in the graph and explain how the changes affect the animal species composition between years 0 and 120. (b) Identify TWO biotic and TWO abiotic factors and discuss how each could influence the pattern of ecological succession. (c) Design a controlled experiment to determine how the diversity of plant species in a newly abandoned field would be affected by large herbivores. Questions 3 and 4 are 2012 Free-Response questions which may be found at http://apcentral.collegeboard.com/apc/public/repository/2012_frq_biology.pdf. The scoring guide for question one is found at http://apcentral.collegeboard.com/apc/public/repository/ap12_biology_scoring_guidelines.pdf 3. An agricultural biologist was evaluating two newly developed varieties of wheat as potential crops. In an experiment, seedlings were germinated on moist paper towels at 20ºC for 48 hours. Oxygen consumption of the two-day-old seedlings was measured at different temperatures. The data are shown in the graph below. (a) Calculate the rates of oxygen consumption in mL/min for each variety of wheat at 7°C and at 17°C. Show your work (including your setup and calculation). (b) Explain the relationship between metabolism and oxygen consumption. Discuss the effect of temperature on metabolism for each variety of seedlings. (c) In a second experiment, variety A seedlings at both temperatures were treated with a chemical that prevents NADH from being oxidized to NAD+. Predict the most likely effect of the chemical on metabolism and oxygen consumption of the treated seedlings. Explain your prediction. 4. Information flow in cells can be regulated by various mechanisms. (a) Describe the role of THREE of the following in the regulation of protein synthesis: RNA splicing repressor proteins methylation siRNA (b) Information flow can be altered by mutation. Describe THREE different types of mutations and their effect on protein synthesis. (c) Identify TWO environmental factors that increase the mutation rate in an organism, and discuss their effect on the genome of the organism. (d) Epigenetics is the study of heritable changes in the phenotype caused by mechanisms other than changes in the DNA sequence. Describe ONE example of epigenetic inheritance.