Life Sciences P2 Standardised MG 2016 EW hlayiso.com

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE EXAMINATION NOVEMBER 2016 LIFE SCIENCES: PAPER II MARKING GUIDELINES Time: 2 hours 100 marks These marking guidelines are prepared for use by examiners and sub-examiners, all of whom are required to attend a standardisation meeting to ensure that the guidelines are consistently interpreted and applied in the marking of candidates' scripts. The IEB will not enter into any discussions or correspondence about any marking guidelines. It is acknowledged that there may be different views about some matters of emphasis or detail in the guidelines. It is also recognised that, without the benefit of attendance at a standardisation meeting, there may be different interpretations of the application of the marking guidelines. IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 2 of 8 SECTION A QUESTION 1 1.1 1.1.1 interspecific competition 1.1.2 resource partitioning/niche partitioning 1.1.3 secondary succession 1.2 1.2.1 closed – fences have been erected around reserve 1.2.2 (a) immigration (b) Logistic growth/ S shaped/ sigmoid curve of impala Population size Impala shape axes numbers Time/weeks/months 1.3 1.3.1 vegetation/trees would become scarce/damaged; young, old and infirm giraffe would start dying/starving fewer giraffe births; giraffe would become thin/weaker/poor condition; aggression in adults increase in predator population ; increase in disease 1.3.2 culling; to shoot excess numbers; selling giraffe to other reserves; introducing larger predators to feed on them; giraffe contraception to reduce numbers open up to hunting to reduce numbers/ to kill excess 1.3.3 census/aerial photographs; animals are large enough to be easily seen/ counted 1.4 Hunting at different times of day avoid chasing same prey; leopards kill buck; scavengers eat leftovers territorial behaviour – protection of food sources Other suitable answers. 1.5 No/do not agree: re-establish overgrazed land; prevent erosion; returning natural habitat; allows increase in biodiversity; investing in training local workforce; increase skills of people; education/conservation programmes to teach about wildlife; research done on indigenous plants and animals. Yes/agree: land should be reclaimed for farming; is an important agricultural area; SA has a shortage of arable land; increasing population could lead to food shortages; farm not open to public/tourists, so no benefit to locals; human interference could have negative consequences in long run, e.g. lead to culling. IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 3 of 8 1.6 1.6.1 predator-prey/predation predatory 1.6.2 (a) shows the amount of the producers/food for the impala; helps to give a clearer understanding of all the factors that influence the size of the impala population; gives better understanding of the relative mass of grass/producers supporting this food chain reflect balance of resources between in food chain; allows one to see whether the impact on impala is due to predation/food i.e. an elaboration of the balance (b) the impala numbers had increased and more grass was eaten 1.6.3 individual/single grass plants would be very large numbers; gives a more accurate reflection of how much grass supports the impala population biomass is an indicator of energy requirements at each trophic level 1.6.4 550 – 600 kg (÷ 45 kg) = 12/13 leopard QUESTION 2 2.1 2.1.1 they have a division of labour/different jobs are done by a variety of bees/ there are different castes/queen, drones and workers are present/queen lays eggs while workers do different jobs either a description of a job or mention of the fact that there are different jobs 2.1.2 bees ensure seed production/the continuation of plants/pollination i.e. food for livestock; plants produce food for humans/other animals such as livestock/without bees there would be no food for livestock (and therefore humans)/food security 2.2 2.2.1 Drones 2.2.2 Propolis 2.2.3 Pollination 2.2.4 CCD 2.3 2.3.1 increase until 1960/61; then decline until 1988–89 after which it increases slightly until 1992/3 (max 2) 2.3.2 1992/3–1997/1998 2.3.3 2040–2055 2.3.4 density-dependent – many bees close together in a nest cause the disease to spread more quickly IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 4 of 8 2.4 2.4.1 Table showing stages in the life cycle of worker bees and their roles in the colony Age/stage of worker bee Role/job (weeks) 1/birth–1 Clean out dirty honeycomb; feed larvae 2/1–2 Build honeycomb; collect food from foragers 3/2–3 Guard the hive; remove corpses 3–5/7 Forage for nectar, pollen, water 5–7 Dies Heading: Headings of columns: Age ranges all correct: Correct jobs: 1–2 correct 3–5 correct 2.4.2 patrol and defend territories; become very aggressive if threatened; signalling behaviour head butting to show aggression/ward off threat/ foreign bees; need to protect their food supply and nectar when there is a shortage of nectar-producing flowers (How and why must be linked) 2.5 Disease: American Foulbrood disease is a highly contagious disease; AFB destroys entire colonies; as there is no known cure it could wipe out all SA's bees/hives can be destroyed/reducing the number of bees pollinating of crops will not take place less food for South Africans spores can survive for half a century/40% bees killed in W Cape already this year; disease infects embryos OR Access to food for bees: Expansion of urban areas into viable forage land is greatly affecting access to food for bee colonies/can lead to many bees dying of starvation; pollinating of crops will not take place = less food for South Africans. no space for nests Answer must be integrated – explanation of threat good elaboration of importance to SA 2.6 2.6.1 large mammals/big five are tourist attractions/bees are small, not highly visible insects/bees annoyance to humans/size leads to them being overlooked/small number of rhino (other suitable answer) 2.6.2 more important to conserve bees; as whole food chains/food resources for most animals depend on bee pollination; endangered mammals dying out will not directly influence our livelihood/remaining alive; bees have much greater role in maintaining biodiversity IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 5 of 8 QUESTION 3 ESSAY MEMO FOR POLICY AGAINST POLICY A: • Far more births than deaths. • Declining ages 5–19. B: • Population approximately trebled since 1950. • 2015 growth rate only 0,89%/slowing down. • Approximately 4 times greater population • SA density is much less than other countries. density. • 44 people per m2 – stress of resources (Max 1 mark for use of stats) • 24th largest country in the world. • Age dependency ratio unfavourable. • Pressure on productive population in South C: Africa is high. • Less than 50% responsible for the rest. D: • Tsunami – world cannot support more people. • Resources are finite. • Growth rate exponential. E: • AIDS/HIV no longer a death sentence. • Life expectancy has improved. • Infant mortality rate has decreased, more • Overall standing of living has improved. babies surviving. • SA can afford more births. • Life expectancy has improved. • AIDS still responsible for higher than normal no. of deaths • SA has high infant death rate • Life expectancy still not as high as 1990 level • Forced sterilisations and abortions F: • Unethical/against human rights G: • Overpopulation. • Discrimination. • Environmental degradation. • Need to control immigration, etc. as • Migration and social instability. controlling birth rate is only 1 parameter that • Displacement of people. affects population size. • Exceed sustainable foot print of 1,8 hectare. • Population numbers not only influenced by birth rate but also by migration and war. IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 6 of 8 H: • Policy was effective. • Very intrusive • Positive Impact of limiting children. • Increased abortion/infanticide • Policy led to drop in birth rate – effective • Won't ignite a baby boom • Indicate not many want large families. • Would lead to an aging population • Many children too expensive to raise. • Economic concerns/labour shortage as seen in China • Could increase abortion/ sterilisation rates, etc. (max 2) • Skewed sex ratio – very few females • Increased infanticide • Many people did not want large families • Many children – very expensive to raise OWN: • Declining children will lead to less revenue = • Global warming; desertification = less arable pressure on healthcare, pensions, etc. land; leads to food insecurity. • Can lead to eugenics movements xenophobia, • Over-population lower carrying capacity etc. • Exceed carrying capacity by 2050 • Social implications – spoilt children • Shape of pyramid indicates increased demand • Education can limit birth rate on resources in future • Can lead to eugenics movements. (selective • Would reduce abuse of child grants breeding to improve human genetic make-up) • SA has limited work opportunities • Psychological/social impact to of one child families • Education can reduce birth rate • Can result in twins being separated at birth • Limit on birth rate won't lower SA footprint • Once carrying capacity is exceeded - numbers will drop anyway. • Certain religions don't believe in contraception or policies to limit the birth rate Details will be expanded at standardisation of memo at marking session. (Will include arguments for source facts in SA context. Relating source facts to SA context will be discriminator for scientific merit and an excellent essay.) Using the SA context will lead to high integration of facts Do not mark alternative solutions or discriminatory statements. Write FOR, AGAINST or NO DECISION at top of the page! Total: 100 marks IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 7 of 8 Note: Essay should be 2½ to 3 pages in length. Time allocation suggestion: Reading of sources 10 min.; Planning 10 min.; Writing essay 40 min. Possible mark 1 mark 2 marks 3 marks 4 marks (40) • Decision given • Decision given • Decision given • Key points present for and • Key points developed for • Key points developed for Planning against the argument and against the argument and against the argument 6 ×2 • Source references identified (e.g. Source A/own information) • Vague • Clear decision made Decision • Changed position within 2 essay Use of knowledge • Up to ¼ of potential detail • Up to ½ of potential detail • Up to ¾ of potential detail • Source detail – very close from sources in sources used to support in sources used to support in sources used to support to full potential used to 8 ×2 argument (1–3) argument (4–6) argument (7–9) support argument (10) • Some facts given beyond • Many facts given beyond • Some facts given beyond • Many facts given beyond the source to support the source to support the source to support the source to support Use of own knowledge argument (1) argument (1) argument argument 4 • Facts integrated into the • Facts integrated into the argument (1) argument (1) • Repetition mostly avoided • Repetition mostly avoided • Some minor digression • Some minor digression • Supporting argument • Supporting argument Content Relevance 2 relevant relevant • Quality of source extracts acknowledged • Writing consists of facts • Maximum if no clear • Supports the position • Strongly supports a clear with little linkage or decision in support • Reasoning is clear position Quality of argument reasoning • Reasoning correct, but hard • Minor errors in flow • Reasoning is very clear and supporting • Reasoning incorrect to follow • Linkage sometimes missed succinct 8 decision • Ordinary: some linkage • Flow is logical ×2 evident • Compelling with regular linkage • Well-integrated argument IEB Copyright © 2016 PLEASE TURN OVER

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE: LIFE SCIENCES: PAPER II – MARKING GUIDELINES Page 8 of 8 Possible mark 1 mark 2 marks 3 marks 4 marks (40) • One to two counter • Three to four counter • Integration of one to two • Integration of three to four Fairness – counter opinions given from the opinions given from the counter opinions from the counter opinions from the 4 opinions to decision sources sources sources into argument sources into argument • Writing is almost • Tone, language, • Tone is consistent and • Tone is mature and suited unintelligible terminology weak suited to scientific to scientific language • Tone, language, • Introduction and language • Excellent and appropriate terminology unscientific conclusion present • Good and appropriate language and terminology Presentation and very weak language and terminology • Correct paragraphing with 4 • Introduction and/or • Mostly appropriate good transitions conclusion not present paragraphing • Interesting introduction, • Introduction and satisfying conclusion conclusion have merit Scientific merit Essay shows academic rigour, accurate reasoning, insight and cohesiveness. 2 IEB Copyright © 2016