Life Sciences Grade 12 P2 NSC Supplementary 2012 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P2 VERSION 2 (OLD CONTENT) FOR PART-TIME CANDIDATES FEBRUARY/MARCH 2012 MEMORANDUM MARKS: 150 This memorandum consists of 11 pages. Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 2 DBE/Feb.–Mar. 2012 NSC – Memorandum PRINCIPLES RELATED TO MARKING LIFE SCIENCES 2012 1. If more information than marks allocated is given Stop marking when maximum marks is reached and put 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. 7. 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-recognized 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 recognizable, accept, provided it does not mean something else in Life Sciences or if it is out of context. 13. If common names given in terminology Accept, provided it was accepted at the National memo discussion meeting. Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 3 DBE/Feb.–Mar. 2012 NSC – Memorandum 14. If only letter is asked for and only name is given (and vice versa) No credit. 15. If units are not given in measurements Memorandum will allocate marks for units separately, except where it is already given in the question. 16. Be sensitive to the sense of an answer, which may be stated in a different way. 17. Caption Credit will be given for captions to all illustrations (diagrams, graphs, tables, etc.) except where it is already given in the question. 18. 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. 19. No changes must be made to the marking memoranda. In exceptional cases, the Provincial Internal Moderator will consult with the National Internal Moderator (and the External moderators if necessary). 20. Only memoranda bearing the signatures of the National Internal Moderator and the UMALUSI moderators and distributed by the National Department of Basic Education via the Provinces must be used in the training of markers and in the marking. Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 4 DBE/Feb.–Mar. 2012 NSC – Memorandum SECTION A QUESTION 1 1.1 1.1.1 B33 1.1.2 B33 1.1.3 A33 1.1.4 C33 1.1.5 D33 (5 x 2) (10) 1.2 1.2.1 Non-biodegradable3 1.2.2 Biogeography3 1.2.3 Extinct3 1.2.4 Vestigial3/vestige 1.2.5 Biodiversity3 1.2.6 Continental drift3 (6) 1.3 1.3.1 A only33/A 1.3.2 Both A and B33/A and B/Both 1.3.3 Both A and B33/A and B/Both 1.3.4 A only33/A 1.3.5 Both A and B33/A and B/Both 1.3.6 B only33/B 1.3.7 Both A and B33/A and B/Both (7 x 2) (14) 1.4 1.4.1 Jurassic period3 (1) 1.4.2 - In the beginning of the Tertiary Period the number of reptile species was large3 - and decreased 3 towards the middle of the period - Towards the end of the Tertiary Period the number of reptile species remained stable.3 - In the beginning of the Tertiary Period the number of mammal species was very small3 - but towards the end of the Tertiary Period the number of mammal species increased3 (any 4) (4) 1.4.3 Fish3 and amphibians3 (2) 1.4.4 Birds are more closely related to reptiles3. They share3 a(n) immediate/more recent common ancestor3 (3) (10) Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 5 DBE/Feb.–Mar. 2012 NSC – Memorandum 1.5 1.5.1 - Wear rubber gloves when taking the samples3 so as not to get contaminated with germs3 - Samples should be taken by using a container/bottle attached to a string 3 to avoid stepping too close to the river bank/prevent drowning/falling into water /contamination (Mark first TWO only) (4) 1.5.2 Temperature of the human body3 at which the bacterium normally lives3/E coli normally lives in the large intestine of humans/human body temperature is 37˚C/ to allow bacteria to reproduce33 (2) 1.5.3 River Y3 (1) 1.5.4 The chemical indicator changed colour which indicates the presence of E. coli3/which is a positive test for E. coli (1) 1.5.5 - Lack /Absence of proper sewage systems3/poor hygiene/ bacteria in water results in faeces getting into water 3 - People swimming/washing in the river 3 (2) (10) TOTAL SECTION A: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 6 DBE/Feb.–Mar. 2012 NSC – Memorandum SECTION B QUESTION 2 2.1 2.1.1 803km (1) 2.1.2 As we move away from the city centre the number of lichens3 and white moths increase3while the number of dark moths3 decrease3 (4) 2.1.3 Since industrial areas are more polluted3and lichens grow in unpolluted areas3/are sensitive to pollution (2) 2.1.4 The number of white moths will increase3 and the number of black moths will decrease3 (2) 2.1.5 - Less pollutants will be released3 and the tree trunks will be lighter /less dark and therefore3 - The light moths are less visible3 / while the dark moths will be more visible to predators - And will suffer a lower/higher mortality3 - White moths are better camouflaged3/dark moths are not camouflaged (any) (4) (13) 2.2 2.2.1 An increase/decrease in the concentration of sodium disulphate3 will result in an increase/decrease in the percentage germination3 of oat seeds OR An increase/decrease in the concentration of sodium disulphate3 will have no effect on the percentage germination of oat seeds3 (2) 2.2.2 Concentration of sodium disulphate 3 (1) 2.2.3 Temperature3 Water3 Light3 Nutrients/minerals3 Mark first TWO only) (any) (2) 2.2.4 To determine the average estimate3 which increases reliability 3 (2) 2.2.5 12+13+14+11+12/62÷1003 = 62%3 (2) 2.2.6 When oats seeds were germinated in 0,00% concentration of sodium disulphate germination percentage was high3compared to when germinated in 2,50% concentration of sodium disulphate3 (2) [11) Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 7 DBE/Feb.–Mar. 2012 NSC – Memorandum 2.3 2.3.1 Natural selection 3 (1) 2.3.2 As a result of genetic variation 3 in the cactus population some plants have thorns 3 and others do not. The buck prefers to eat the cactus without the thorns3 – the cactus without thorns will not survive 3 The cactus with thorns will survive3 and reproduce 3 offspring with thorns Genes 3 /genotype for thorns were passed on to subsequent generations. (any) (5) (6) [30] QUESTION 3 3.1 3.1.1 The limbs are similar in structure9 suggesting a similar/common origin/ancestor9 (2) 3.1.2 The bones are long9/thin and therefore light to enable the bat to fly 9 OR The thin membrane9 forms a wing9/large surface area for flying3 (2) (4) 3.2 3.2.1 A – Gorilla3 B – Modern Human3 (2) 3.2.2 Gorilla/A Modern human/B 1. Canines well developed3/form fangs 1. Canines not well developed 3 2. Sloping face3 2. Flat face3 3. Brow-ridge well developed3 3. Brow-ridge less developed3 4. Proportionally smaller cranium3/brain 4. Proportionally large cranium3/brain 5. Proportionally wider cheek bone3 5. Proportionally narrower cheek bone3 6. Sagittal crest3 on top of the skull 6. No sagittal crest3 7. Foramen magnum towards the back3 7. Foramen magnum towards the of the skull centre3of the skull/more forward 8. Chin not well developed3 8. Chin well developed3 9. No pronounced forehead3 9. Pronounced forehead3 (Mark first FOUR only) (any 4 x 2) 1 mark for table (9) Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 8 DBE/Feb.–Mar. 2012 NSC – Memorandum 3.2.3 B3 (1) 3.2.4 - Allows total awareness3 of the environment in sensing (2) danger3/looking for food - Enables hands to be free3 to use implements3/carry objects or offspring/throw/protect - Exposes a large surface area3 for thermo-regulation3/lose body heat to surroundings in hot conditions/reduce overheating therefore reduce need for water - Small surface area exposed to the sun3, thus reducing over- heating3 - Display of male/female sex organs3 as part of courtship (4) behaviour3 3.2.5 (Mark first TWO only) (any 2 x 2) - Capable of upright posture3 - Long upper arms3 - Freely rotating arms3 - Elbow joints allowing rotation of forearm3 - Rotate hands at least 180º3 - Flat nails instead of claws3/bare finger tips - Opposable thumbs3/which work in opposite direction to their fingers - Large brains/cranium compared to their body mass3 - Eyes in front3/binocular vision/stereoscopic vision - Eyes with cones3/colour vision - Sexual dimorphism3/distinct differences between male and female - Olfactory brain centres reduced3/reduced sense of smell - Parts of the brain that process information from the hands and (1) eyes are enlarged3 (17) - Two mammary glands only3 any (Mark first ONE only) 3.3 Uranium3 will be used, because dinosaurs lived 66 million 3 years ago and carbon-14 can only measure up to 57303 years ago (3) 3.4 3.4.1 53 mya3 (2) 3.4.2 A3 (1) 3.4.3 Chimpanzee 3 (1) 3.4.4 98,63%3 (2) (6) [30] TOTAL SECTION B: 60 Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 9 DBE/Feb.–Mar. 2012 NSC – Memorandum SECTION C QUESTION 4 4.1 4.1.1 Annual catches of herring and cod over 8 years 400 Catches (thousands of tons) 350 300 250 200 Herring 150 Cod 100 50 0 1 2 3 4 5 6 7 8 9 Year Rubric for the mark allocation of the graph Correct type of graph 1 Title of graph (both 1 variables) Correct label for X-axis 1 Graphs labelled/key 1 provided for 2 graphs Correct label for Y-axis 1 including unit All points joined for graph A 1 All points joined for graph B 1 Appropriate scale for X-axis 1 Appropriate scale for Y-axis 1 Drawing of the graphs 1–1 to 8 points plotted correctly 2–9 to 15 points plotted correctly 3–all 16 points plotted accurately (12) NOTE: If the wrong type of graph is drawn: − marks will be lost for 'correct type of graph' − marks will be lost for joining of points If graphs are not drawn on the same system of axes − mark the first graph only using the given criteria If axes are transposed: − marks will be lost for labelling of X - axis and Y- axis Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 10 DBE/Feb.–Mar. 2012 NSC – Memorandum 4.1.2 Herring population shows a sharp decline3 from year 1 to 23 and then a steady decline3 until year 7 3and then a small increase3 (any) (4) 4.1.3 - Limit the size of fish caught3 - Limit the number/quotas of fish caught3 - Limit the fishing area3 - License to fish3 - Develop legislation3to regulate fishing - Heavy penalties for flouting the legislation3 - Scientific research3 to inform legislation - Minimal or no fishing during breeding season3/limited fishing season - Education and awareness of endangered species3 - Encourage mariculture3/sea farming - Discouraging illegal market by government selling it at lower price3 - Stricter monitoring3 (Mark first TWO answers only) (any) (2) (18) 4.2 4.2.1 Testical tumours3 Enlargement of prostate gland3 Urinary infections3 Constipation3 HIV/AIDS3 Cancer3 (any) (2) (Mark first TWO only) 4.2.2 Sustainable harvesting3 Research3- done to look at reproductive cycle Legislation3- control harvesting Penalties 3for breaking legislation Education3/campaign Establish nurseries3 Establish more nature reserves3 Provision of free3/cheaper food - (Mark first THREE only) (any 3 x 1) (3) 4.2.3 Plants can become extinct3/lead to loss in biodiversity Food chains/webs can be destroyed3 Shortage of food3 Could lead to degradation of the environment3 Erosion of ground surface if too many plants are removed3 Increase run-off of water3 Destroy habitats of many organisms3 Alien plant invasion3 Upset the balance of oxygen and carbon dioxide3/global warming (Mark first TWO only) (2) (7) Copyright reserved Please turn over

Downloaded from hlayiso.com Life Sciences/P2 (Version 2) (Part-time) 11 DBE/Feb.–Mar. 2012 NSC – Memorandum 4.3 Management strategies to manage solid waste Landfill and burning with energy recovery3 - Utilise the heat generated 3from the burning of landfill sites to generate electricity3 thus saving on the electricity bill3 - Investigate methods to collect and utilise methane gas as a fuel3 (any) (3) Recovery and recycling3 - Encourage citizens of the city to put different types of waste3 into different waste containers3/bins of different colours - Partnership with recycling companies for improved collection of different wastes3 - Fines3 for people that do not separate the waste into different bins - This could generate income3 and reduce the transport cost 3 - Educate people to use organic waste3 for example to make compost3 which could fertilise soil, they can plant vegetables (any) (3) Educate citizens and companies to reuse3 waste - Glass3 containers for milk, cold drinks and alcohol etc. - This will reduce the need to produce more of these items3 - thus saving energy and money3 (any) (3) Reducing waste3 - Charge/penalties people extra if they generate more waste3 - Encourage citizens to manage waste more efficiently3/renewable (3) (12) ASSESSING THE PRESENTATION OF THE ESSAY Marks Description 3 Well structured – demonstrates insight and understanding of question 2 Minor gaps in the logic and flow of the answer 1 Attempted but with significant gaps in the logic and flow of the answer 0 Not attempted/nothing written other than question number Synthesis (3) (15) TOTAL SECTION C: 40 GRAND TOTAL: 150 Copyright reserved