Life Sciences Grade 12 Paper 2 NSC June 2013 Memo

Downloaded from hlayiso.com basic educhtion““ Department: Basic Education Hones BAG X REPUBLIC OF S p 00 SENIOR CERTIFICATE EXAMINATION BIOLOGY P2 HIGHER GRADE 2013 POSSIBLE ANSWERS MARKS: 200 This memorandum consists of 14 pages. Copyright reserved Please turn over

Downloaded from hlayiso.com Biology/HG/P2 2 DBE/2013 i ailahel DEPARTMENT OF BASIC” EDUCATION PRINCIPLES RELATED TO MARKING HG & SG BIOLOGY 2013 This document should be attached to ail memoranda after the question paper Ag been written and made available to ALL Life Sciences/Biolqgy teacherssié GAG > +10 PRETORIA 0001 _ If more information than marks allocated is given PUBLIC EXAMINATIONS Stop marking when maximum marks are reached and puf a Wavy line and max in the right-hand margin. 2. If, for example, three reasons are required and five are given Mark the first three irrespective of whether all or some are correct / incorrect. 3. if whole process is given when only part of it is required Read all and credit relevant part. 4. If comparisons are asked for and descriptions are given Accept if differences / similarities are clear. 5. If tabulation is required but paragraphs are given Candidates will lose marks for not tabulating. 6. If diagrams are given with annotations when descriptions are required Candidates will lose marks. c If flow charts are given instead of descriptions Candidates will lose marks. 8. if sequence is muddled and links do not make sense Where sequence and links are correct, credit. Where sequence and links are incorrect, do not credit. If sequence and links becomes correct again, resume credit. 9. Non-recognised abbreviations Accept if first defined in answer. If not defined, do not credit the unrecognised abbreviation but credit the rest of answer if correct. 10. Wrong numbering If answer fits into the correct sequence of questions but the wrong number is given, it is acceptable. 11. If language used changes the intended meaning Do not accept. 12. Spelling errors If recognisable accept provided it does not mean something else in Biology or if it is out of context. 13. If common names given in terminology Accept provided it is accepted at this memo discussion. Copyright reserved _ GM. Wiese Please turn over External Moderator malusi

Downloaded from hlayiso.com Biology/HG/P2 3 DBE/2013 ee ena DEPARTMENT OF BASIC EQUCATION 14. If letter only is asked for and name only is given (arid vice versa) No credit. 2013 -06- 05 15. If units are not given in measurements PRIVAIE BAG 4 11d Candidates will lose marks. Memorandum will allocate marks-for. finite. ue separately. PUBLIC EXAMINATIONS 16. Be sensitive to the sense of an answer, which may be stated in a different way. 17. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption. 18. If you have doubts consult the other language memo. If you still have doubts ask the Provincial Internal Moderator to contact the National Internal Moderator or the External Moderator(s). 19. Code-switching of official languages (terms and concepts) A single word or two that appears in any official language other than the learners’ assessment language used to the greatest extent in his/her answers should be credited, if it is correct. A marker that is proficient in the relevant official language should be consulted. This is applicable to all official languages. 20. Nochanges may be made to the marking memoranda without consulting the Provincial Internal Moderator who in turn will consult with the External Moderator(s). 21. | Only memoranda bearing the signatures of the UMALUSI moderators and distributed by the National Department of Education via the Provinces may be used. Copyright reserved FM, Wiese Please turn over External Moderator Umatusi

Downloaded from hlayiso.com Biology/HG/P2 SECTION A QUESTION 1 1.1 1.4.1 Dvv (12) By 1.1.3 C/DV¥ 1.1.4 AlCVv¥Y 115 BYY 11.6 AY 1.2 1.2.1 CapillarityY” 1.2.2 Turgor( pressure) 4.2.3 Xerophytes ~/ Succulents 1.2.4 Bicarbonate ionsv 12.5 Urethra” 1.2.6 Guttation” 1.3 13.1 Avvonly 13.2 Avvonly 1.3.3 AvVonly 1.3.4 BothAandBvYY 13.5 Bvvonly 1.3.6 BothAandBvYY Copyright reserved SCE — Memorandum DBE/2013 DEPARTMENT OF GASI®” pucaTt 2013 -06- 05 PRIVATE BAG x 110 PRETORIA 0001 PUBLIC EXAMINATIONS (6x2) (42) (6x1) (6) (6x2) (12) FM. Wiese Please turn over Externol Moderator nralusi

Downloaded from hlayiso.com DEPARTME! Fe BAC Biology/HG/P2 5 SCE — Memorandum ERY 13 -115- 14 2013 -06- 05 PiiVATE BAG A isd 1: Impulse¥ PRETORIA 0001 i PUBLIC EXAMINATIONS 2: Sensory/afferent “neuron Central nervous system/interneuronv / spinal cord (In this sequence) 3: Motor/efferent V neuron (4) 1.5 1.5.1 - (Gain) in metabolism ¥ - (Loss) by exhalation” - (Loss) by sweating ¥ (Any2x1) (2) 1.5.2 600+ (24x 3) ¥=8,3v cm3h ¥ (3) 1.5.3 ADH / antidiuretic hormone ¥ (compulsory mark) - is produced when the body is losing too much water as in exercise / produced in order to maintain blood water potential “ - Increases permeability of collecting ducts ¥ - Thus more water is reabsorbed back into the blood - Resulting in a smaller volume of urine Vv (5) (10) 16 16.1 (41.0-41.5)v "Cv (2) 1.6.2 - The only difference between the two camels was the availability of water vv Jalil other factors were the same for both (2) 1.6.3 - Take readings from more camels” under the same conditions - Repeat “ the experiment / on more days - Use camels of the same age Y under the same conditions (any 2x1) (2) 1.6.4 - Hydrated camel was able to sweat more v to cool down” (2) (8) 17 4.7.1 - Auxin ¥ (1) 1.7.2. - Tip of stem / rootY (1) 1.7.3 -1,00 ~mg/t (1) Copyright reserved PML Wiese Please turn over External Moderator ® Imalusi

Downloaded from hlayiso.com Biology/HG/P2 6 DBE/2013 SCE ~ Memorandum 1.74 -The number of adventitious roots increase “as the plant growth substance concentration increases” up to a certain optimum” - High concentration of the plant growth substance inhibits growth v (any 3x1) (3) 1.7.5 - Regulate leaf and fruit abscission ¥ - Responsible for apical dominance “ - Responsible for tropic movements “ - Promotion of the ripening of fruit - Rnhibition of germination of seeds “ - Improve development of fruit ¥ - Increase the plants resistance to infections ” - Help in growth ~/ development / cell division / cell elongation (Any 2) (2) (8) TOTAL SECTION A: 60 DEPARTMENT GF BASIC WW AKBUSATION ~ 2013 -06- 05 PaivAl DAG A id PRETORIA 0691 PUBLIC EXAMINATICN 5 Copyright reserved PH, Wiieseiease turn over External Moderator imalysi

Downloaded from hlayiso.com Biology/HG/P2 7 DEPARTMENGIOF SCE — Memorandum EDUGATION we SECTION B 2013 -08- 05 PRIVATE 8 QUESTION 2 PRETORIA Ooo!” os PUBLIC EXAMINATIONS 2.1.1 Examples of ceil that can be drawn Cell membrane V (can be dubble) Cell membrane OR Elodea cell in salt water Elodea cell in salt water Quality of diagram “ Allow a maximum of: 2 marks, for showing a cell with shrunken contents 1 mark for labelling the cell membrane. 1 mark for caption 41 mark for quality of CORRECT diagram: neat and clear (5) 2.1.2 - Plasmolysis ¥ (1) (6) 2.2 2.2.1 Accept: ~- Passive transport - Osmosis / endosmosis¥ (1) 2.2.2 As the sugar concentration in the beaker increasesv’, the change in mass of the dialysis tubing decreasesv or vice versa (2) SM. Wiese External Moderator Umolusi Copyright reserved Please turn over

Downloaded from hlayiso.com. Biology/HG/P2 2.2.3 8 SCE - Memorandum DEPARTMENT OF BASIC” EDUCATION. DBE/2Z0TS 2013 -08- 05 PRIVATE BAG X 110 Yunit 6; “scale Change in mass of dialysis Change in mass of dialysis tubing in grams in different sugar solutions Y ¥ plotting v 0 5 10 < Y label Sugar concentration in the beakers in % Y type of graph 15 20 25 30 “scale ¥ unit v heading PRETORIA 0C01 PUBLEC EXAMINATIONS Rubric for the assessment of the graph Correct type of graph Title of graph Correct label for X-axis Correct unit for label of X-axis Correct label for Y-axis Correct unit for label of Y-axis Appropriate scale for X-axis afa}o[a}.fo]]o) Appropriate scale for Y-axis Plotting of points for graphs 3: plotted all six points correctly 2: plotted three or more of the points correctly 0: no points plotted 1: plotted two or fess of the points correctly Wrong type of graph is drawn : marks will be lost for “correct type of graph” as well as for “plotting of points” “If axes are transposed : marks will be lost for labels 7 cells - lowers the water potential of the guard cellsY” - leading to endosmosis” from surrounding epidermal cells - Turgor pressure of guard cells increasesY - Thin outer wails of guard cells bulge out” - causing thick inner walls of guard cells to be pulled apart” - leading to an increase in the size of the stomatal pore” - allowing more water vapour to leave Vv Copyright reserved Feernal Moderator imatysi (11) (14) - Glucose” formed during photosynthesis v/ K* ions enter guard (Any 6x1) Please turn over (6)

Downloaded from hlayiso.com [ CRPARTIENT or sxes— Biology/HG/P2 9 EDUanON ec SCE — Memorandum i 2018 -08- 95 oe pate BAG xX 110 2.4.1 Mist “/ Moisture BOR | BLIC EXAMINATIONS 2.4.2 - The group of plants in classroom conditions’ 2.4.3 (4.2 + 7.6 + 11.7) ¥ -(45+7.6+ 11.0) ¥ =04/Y ml (3) 2.4.4 - Connection between plant and tube should be air tight V to ensure that there are no air bubbles in the apparatus v - Cut the twig under water V to prevent air entering the xylem V - Use sharp knife V to prevent damaging the xylem” (Any 2 x 2) (4) (9) (35) Copyright reserved External Medes dulel Please turn over

Downloaded from hlayiso.com | DEPARTMENT GF exer: NT G el Biology/HG/P2 10 finn SUCAT Poy SCE — Memorandum QUESTION 3 2013 -06- 95 PRIVATE BAG x 3.1 PRETORIA dGO) 3.1.14. A-—Ciliary body/muscle ¥ PUBLIC EXAMINATIONS B ~ Suspensory ligaments ¥ 42) 3.1.2 a) Diagram || Y— Ciliary body moves closer to the lensv resulting in slack suspensory ligaments “ (3) b) Diagram | ¥— Pupil is dilatedv’/bigger to allow more light to enter the eye Vv (3) 3.1.3 a)Dv¥ (1) b)FY (1) 3.1.4 - Can change its shape: ¥ - To focus image onto the yellow spot / retina “ - Irrespective of the distance from the eye v / For near or distant vision / accommodation (3) (13) 3.2 3.2.1 (a) - Absence of pain receptors Vv - thus no impulse is generated ¥ - to be interpreted by the brain Vv : (3) (b) - Pain is a protective function ¥ - Part could be lost or damaged ¥ - and lose its function for the body “ - Because the person is unaware of the harm ¥ - Therefore, does not respond appropriately / correctly Vv - Leading to further damage ¥ (Any 5) (5) 3.2.2 (a) A: Optic nerve ¥ C: CerebellumY (2) (b) BY (1) 3.2.3. Vital / reflex processes” such as breathing / heartbeat” will stop W (3) 3.2.4 (a) BY (1) (b) Cv (1) (16) 3.3 - Layer of fat under the skin v’ insulates the penguin against the cold v - Streamlined body Y reduces resistance from water, v / allows the penguin to swim faster to catch fish - Oily feathers V prevent cold water reaching skin “ (6) Copyright reserved GM. Wiese Please turn over External Moderator Umatusi

Downloaded from hlayiso.com Biology/HG/P2 QUESTION 4 4.1 4.1.1 4.1.2 4.1.3 4.2 4.2.1 4.2.2 4.3 4.3.1 4.3.2 4.3.3 Copyright reserved 11 SCE - Memorandum ; ae 16, ARON. : am 2013 -05- 95 PRIVATE B&G & 47 PRETORIA 0004 3000 vem? (2000 + 300 + 100) / 2400 vomp®_ PUBLIC EXAMINATIO = 600 v cm? a EON] - More sweat produced on warm v day -To cool down the body “ (2) On a hot day more liquids taken in W less urination V more sweating v (Mark first two only) (2) ” The volume of urine produced by the kidneys will be higher v in Man A ¥ OR The volume of urine produced by the kidneys will be less Yin Man BY The concentration of urine will be lower” in Man A ¥ OR The concentration of urine will be higher “in Man B W (4) Man A sitting under shade ~/ less active and drinking, hence less water lost through sweat “’/ more water lost through dilute urine Man B runningv / more active, hence more water lost through sweating” / less water lost through urine thus urine more concentrated. (4) (8) In a healthy person: Protein not present” because proteins are large (macromolecules) Y / cannot pass through (filter) In person with disease: damaged tissue Y / glomerulus / Malphighian body allows protein to filter through ¥ (4) - Reabsorption “and Active transport. Vv (2) The urea in urine comes not only from the blood through glomerular filtration’ but it is also added from the blood in the second capillary network during tubular excretion” 7 : : ~ Please turn over GM.Weose External Moderator Umotusi

Downloaded from hlayiso.com DEPARTEN ? BASIC Biology/HG/P2 12 SCE — Memorandum 2018 -06- 95 4.4.1 - It creates a greater surface areav PRIVATE BAG x 40 [E BAG Ri - for the movement of waste substances” into the bathimgstawid'ogn; (2) PUBLIC & “2 4.42 - Useful substances in the bathing liquid bechme-desiteae PAUNATIONS - while waste substances are depositedv into the bathing liquid - to maintain a concentration difference” for the movement of substances (Any 2) (2) 4.4.3 This is the average body temperature V needed for optimal enzyme functioning “ (2) (6) 45 Afferent arteriole ¥ Efferent arteriole V Glomerulus W Bowman’s capsule ¥ PodocyteY Capsular space” Malphighian body of a human nephron Marking criteria: Diagram should show the following: - Efferent arteriole narrower than afferent arteriole VW - Cup shaped ¥ : - Any four (4) correct labels (6) (35) Copyright reserved PM. Wiese Please turn over External Moderator” mabysi

Downloaded from hlayiso.com [ DEPARTHENT OF wxste— Biofogy/HG/P2 13 SCE — Memorandum 2013 -08- 95 QUESTION 5 PRIVATE Bac x PRETORIA over 5.1 PUBLIC EXAMINATIONS 5.1.1 0 ¥—2 ~years / during first “two years after birth (2) 5.1.2 (5,8 - 5,9) — (1,2 -1,5) “= (4,3-4,7) ¥ (2) 5.1.3 Boys: 14 W years ¥ Girls: 13 ¥ (3) 5.14 From the 9"v — 13" vyear (2) 5.1.5 Growth hormone / STH / Thyroxin ” (1) 5.1.6 17-18v (1) 5.1.7 - Females reach the second increase in growth rate/ puberty earlier Y than males - Females reach their final adult sizev earlierv than males - Females have a smallerv adult sizev than males - Between ages 4 and 6vgrowth of the boys is higher than girls, Between 9 and 13 ~ growth rate of girls is higher than boys, “” Between 13 and 18 growth rate of boys is higher than that of girls. ¥ (any 3x2) (6) (17) 5.2 Homeostasis is the maintenance of a constant internal environment “ When the metabolic rate is low ¥ because of low thyroxin concentration the pituitary gland is stimulated V to secrete TSH V which is transported by the blood ” to the thyroid gland which is stimulated to secrete more thyroxinY which is transported to cells Vv to increase the metabolic rate “ If the metabolic rate increases above the normal level “ the pituitary gland is inhibited v therefore less / no TSHY is secreted and therefore less thyroxin Vis secreted The metabolic rate is lowered to normal Vv The autonomic nervous system also influences the metabolic rate through double innervation which functions antagonistically Vv One section is stimulatory, “ while the other section is inhibitory ¥ A constant internal environment ” is thus maintained through negative feedback. W any 15 Copyright reserved FeAl, Vhiese Please turn over External Moderator alas;

Downloaded from hlayiso. com Biology/HG/P2 14 SCE — Memorandum Assessing the presentation of the e: Marks Level description () Did not attempt the question. 4 The key concepts are used randomly to ansWeér-tne+ question and more explanation is needed. There are significant gaps in the logic or flow of the answers. The answer is meaningless. Most of the key concepts are organised in a rather superficial way. There are minor gaps in the logic or flow of the answer. The learner does not demonstrate that he/she is in full control of the relevant subject content. The answer is phrased logically and is well structured. The key concepts are explained in such a way that the answer demonstrates insight and understanding of the relevant subject content / question. Copyright reserved Factual content: Synthesis: TOTAL SECTION C: GRAND TOTAL: 4a EM. Vijose tsar Umafusi as faoi3 15 (18) 35 200