2001 - AP Biology 2001 Scoring Guidelines The materials...

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Unformatted text preview: AP Biology 2001 Scoring Guidelines The materials included in these files are intended for non-commercial use by AP teachers for course and exam preparation; permission for any other use must be sought from the Advanced Placement Program. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein. These materials were produced by Educational Testing Service (ETS), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle. The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association is composed of more than 3,900 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3,500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT®, the PSAT/NMSQT™, the Advanced Placement Program® (AP®), and Pacesetter®. The College Board is committed to the principles of equity and excellence, and that commitment is embodied in all of its programs, services, activities, and concerns. Copyright © 2001 by College Entrance Examination Board. All rights reserved. College Board, Advanced Placement Program, AP, and the acorn logo are registered trademarks of the College Entrance Examination Board. AP® BIOLOGY 2001 SCORING GUIDELINES Question 1 A maximum 4 points for each component. Elaboration point: 1 point for either structure or function after the first 2 points have been earned * = required element to receive elaboration point 1 point 1 point (a) Describe structure (a) Explain how structure is responsible for function (must be linked to structure described) (b) Explain how the structure contributes to the function of the organ system to which it belongs * Shortening of sarcomere (unit) causes contraction • sliding of actin filaments during contraction • number of groups of sarcomeres regulate strength of muscle contraction * Cause a muscle fiber (muscle) to contract (shorten) in the muscular system (muscle) OR movement in muscle Sarcomere * Thin-thick (i.e., actin-myosin or protein) filaments (i.e., myofilaments) • cross-bridges • troponin-tropomyosin complex/Ca++ binding • detailed description of sarcomere (e.g., A-band, Z-line, etc.) Neuron * Cell with dendrites and axon OR axon and dendrites and cell body OR nerve cell with cytoplasmic extensions • myelin sheath/Node of Ranvier • plasma membrane (neurilemma) • Na+/K+ pump-gated channels • synaptic knobs/dendrite membrane receptors • axon hillock (i.e., neck of cell body) Nephron * (Renal) tubules and capillaries (glomerulus) OR * Tubular excretory unit of the kidney • filtering unit • PCT, loop of Henle, DCT, collecting duct • epithelial cells • single layer of epithelial cells 1 point * Generate/conduct/transmit impulses (electrical/chemical signals or messages) • speed of impulse transmission • change in membrane polarity • change in membrane polarity • neurotransmitters • origin of depolarization * Conduct impulses (electrical/ chemical signals or messages) in the nervous system * Filtration of materials from blood • (re)absorption of materials (e.g., HCO3-, NaCl, H2O, glucose, amino acids, vitamins, K+, urea) • tubular secretion of materials (H+, NH4+, K+, drugs, toxins) • counter-current multiplier * Regulates osmolarity/ waste removal/ homeostasis in urinary (excretory) system Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 2 AP® BIOLOGY 2001 SCORING GUIDELINES Question 1 (cont.) Villus * Finger-like (hair-like) projections in small intestine • microvilli (brush border) • capillary bed and lacteals • single-cell layer/simple columnar epithelial • tight junction • goblet cells * Also acceptable: Chorionic villus Finger-like projection in the placenta Capillary * Small(est) blood vessel (i.e., tiny tubes carrying blood) • one-cell layer • simple squamous epithelial (endothelium) • porous (fenestrated) • connects arterioles (arteries,metarterioles) to venules (veins) Alveolus * Air sac OR * Thin (single-celled) layer • simple, squamous, epithelial cells • moist permeable membrane • surfactant • thin basement membrane * Absorption of digested material (nutrients) • increase surface area • secrete mucus * Increases amount of surface area for absorption of nutrients in digestive system Maternal-fetal exchange for nutrients, gases, etc. Increases surface area for exchange in the reproductive system during fetal development * Movement of material (gases, nutrients, wastes, hormones, etc.) across capillary membrane • increases surface area • blood cells moving through one at a time • low pressure • slowest velocity of blood • allows passage (conduit) for white blood cells • heat dissipation * Increases vessel contact with all body cells for the exchange of substances between body cells and blood in the circulatory system OR increases surface area in the circulatory system OR a description of a capillary network in the circulatory system * Allows gas diffusion (site to site) • surface area (High SA/V ratio) • close association with capillaries • reduces surface tension, prevents collapse of alveolus • enhance diffusion * Increases amount of surface area which allows for the exchange of gases in respiratory system Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 3 AP® BIOLOGY 2001 SCORING GUIDELINES Question 2 2. (a) A maximum of 6 points may be given for part (a). A single point may be awarded for each concept that follows. Beware of anything that sounds like a Lamarckian statement. • • • • • • • 2. (b) Reproductive potential — the ability to over produce Variability — inheritable changes or mutations linked to variability Limited resources — biotic or abiotic Competition — intraspecific struggle for existence Differential Reproduction — reproductive success of variants Generations — time needed for evolution to occur Elaboration — expansion of Darwin’s ideas such as the effects of environmental change or artificial selection or good, linked example A maximum of 6 points can be scored in part (b). A student may not receive a total score of ten without attempting to respond to three sections of part (b). A single point may be awarded for each of the following: (i) 1 point 1 point Different species exhibit adaptations as a result of the same environment Correct descriptive example linked to biome and survival value or linked to natural selection (ii) 1 point 1 point An inherited characteristic enables the organism to resist the effect of the toxin Specific example, mechanisms of resistance, or extensive elaboration or link to natural selection (iii) 1 point 1 point A single population divides into two reproductively isolated populations or equivalent (use of gene pools) Role of barriers in speciation or discuss gene pool separation or link to natural selection (iv) 1 point 1 point Define or describe the behavior Give a clear example of how this behavior enhances survival or link to natural selection (v) 1 point 1 point Survival value of heterozygote over both homozygotes An example of how the heterozygous enhances the survival of the organism or link to natural selection Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 4 AP® BIOLOGY 2001 SCORING GUIDELINES Question 3 3. (a) 4 points possible 1 point for proper orientation of graph (independent variable on x-axis) 1 point for graph (all of the elements below must be present) • • Uniform spacing of units Correct labeling of axes • proper numbering (a minor error acceptable) • X-axis label: “Time”/ “Hour”/a.m., p.m. labels/a conversion to integers requires unit label as well • Y-axis: oxygen label and mg/L Unit 1 point for correct plot of data points • • • No connecting line necessary No point if more than one data point is misplotted No point if there is a solid extrapolation line beyond the 6:00 a.m. data point to the origin or the 12 midnight data point 1 point for drawing the cloudy day prediction Line/Curve (all of the elements below must be present) • • • 3. (b) Distinguish between the two curves with a legend or direct labeling of one curve Position completely under the bright-day curve (may touch toward the tails) There must be some curve to the line (no flat lines) 5 points possible 1 point Photosynthesis: production of O2 correlated with light changes (i.e., explains changes in shape of bright-day curve). The student must link photosynthesis to increase in light to increase in O2 production. The student must use the term “photosynthesis” or an excellent replacement such as the chemical equation for the process. 1 point Respiration: consumption of O2. Must link respiration to decrease in O2. The student must use the term “respiration” or an excellent replacement such as the chemical equation for the process or the name of another appropriate process such as “decomposition.” 1 point Description of the interaction of the above: photosynthetic rate changes while respiration rate remains relatively constant. 1 point Overcast prediction curve explanation • • Reduced light leads to decreased photosynthetic O2 production, etc. No point given if there is no prediction line/curve on the graph. 1 elaboration point (maximum) for any one of the above. Examples of elaboration may include, but are not limited to: • • • • Water split/photolysis to produce O2 in the light phase, etc. Balanced equation for photosynthesis or respiration (unless used as a substitute for the term above) Description of “light phase” processes (photosystem II, etc.) Gross vs. net productivity Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 5 AP® BIOLOGY 2001 SCORING GUIDELINES Question 3 (cont.) 3. (c) 3 points possible 1 point for describing (predicting) a change in lake conditions such as (must be related to the question) • • • • • increased/decreased O2 increased/decreased biomass or numbers of organisms increased/decreased CO2, long-term or short-term changes no change 1 point for an explanation of the prediction above (may include toxic effects due to significant changes in pH, altered osmolarity, etc.) 1 elaboration point for the explanation of the prediction above or long term ecological consequences to lake. Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 6 AP® BIOLOGY 2001 SCORING GUIDELINES Question 4 4. (a) 4 points maximum Chemical composition — 2 points maximum 1 point amino acids are the basic building blocks of proteins 1 point amino acids contain amino, carboxyl and R groups or correct structural formula showing amino, carboxyl, and R group attached to central carbon or proteins are composed of carbon, hydrogen, oxygen and nitrogen 1 point R group determines the identity/properties of the amino acid Elaboration 1 point for a description of addition of lipids, carbohydrates, and/or prosthetic group Levels of structure — 3 points maximum (Note: to obtain any points, response must name level or list in correct order.) Primary structure — 1 point • • • sequence (chain, string) of amino acids or the number and order of amino acids amino acids linked by peptide bonds amino acids bonded through dehydration synthesis Secondary structure — 1 point • • helix and/or pleated sheet hydrogen bonds (between carboxyl and amino groups) Tertiary structure — 1 point • • • single polypeptide chain forms globular shape hydrogen, ionic, disulfide, and van der Waals bonds, and/or hydrophobic interactions (if hydrogen must have more than one) interaction between R groups Quaternary structure — 1 point • • • more than one polypeptide or subunit hydrogen, ionic, disulfide, and van der Waals bonds, and/or hydrophobic interactions (if hydrogen must have more than one) interaction between R groups Elaboration — 1 point • • explanation of domains explanation of chaperones Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 7 AP® BIOLOGY 2001 SCORING GUIDELINES Question 4 (cont.) 4. (b) 4 points maximum Global understanding of information flow — 1 point • • information in DNA is transcribed to mRNA which is translated into protein DNA contains the information that ultimately determines the sequence of amino acids in the protein Roles DNA — 1 point • codes for RNA, mRNA, tRNA, or rRNA mRNA — 1 point • codes for amino acid sequence tRNA — 1 point • • brings the correct amino acid to the ribosome/mRNA contains anticodon complementary to codon rRNA — 1 point • forms part of ribosome Elaboration — 1 point • • • • 4. (c) intron removal by RNA/snRNP/snRNA alternative splicing provides protein diversity acts as ribozyme/involved in formation of peptide bond rRNA finds and binds start AUG of mRNA (in prokaryotes) 4 points maximum Role in membrane structure — 2 points maximum 1 point — description of integral and/or peripheral proteins 1 point — membrane synthesis 1 point — defines membrane sidedness Membrane function other than transport 1 point — receptors 1 point — enzymes 1 point — cell to cell communication 1 point — anchoring of cytoskeleton or extracellular matrix 1 point — spatial configuration of reaction pathways (e.g., electron transport system) 1 point — cell recognition 1 point — cell junctions Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 8 AP® BIOLOGY 2001 SCORING GUIDELINES Question 4 (cont.) Role in transport — 3 points maximum 1 point — transport proteins may be specific 1 point — process may require direct input of energy (e.g., use of ATP) 1 point — description of transport mechanisms (bind molecule, conformational change, release molecule) or description of how proteins form channels and move molecules through them Elaboration — 1 point • • • • description of a specific transport system (e.g., ATP synthase, Na+/K+ pump, receptor mediated endocytosis) description of chemiosmosis more than one molecule transported (e.g., symport, antiport) may be regulated by electrical or chemical stimuli (gated channels) Copyright © 2001 by College Entrance Examination Board. All rights reserved. Advanced Placement Program and AP are registered trademarks of the College Entrance Examination Board. 9 ...
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This note was uploaded on 08/19/2010 for the course BIOLOGY 101 taught by Professor Mancino during the Spring '10 term at Abant İzzet Baysal University.

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