LIFE SCIENCES P2 MEMO GR11 NOV2020 English hlayiso.com

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2020 LIFE SCIENCES P2 MARKING GUIDELINE (EXEMPLAR) MARKS: 150 This marking guideline consists of 12 pages.

Downloaded from hlayiso.com 2 LIFE SCIENCES P2 (EC/NOVEMBER 2020) PRINCIPLES RELATED TO MARKING LIFE SCIENCES 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 a part of it is required Read all and credit the relevant part. 4. If comparisons are asked for but descriptions are given Accept if the 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 become 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 the 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 the answer, provided it does not mean something else in Life Sciences or if it is out of context. 13. If common names are given in terminology Accept, provided it was accepted at the national memo discussion meeting. 14. If only the letter is asked for but only the name is given (and vice versa) Do not credit. Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2020) LIFE SCIENCES P2 3 15. If units are not given in measurements Candidates will lose marks. Marking guideline will allocate marks for units separately. 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. Code-switching of official languages (terms and concepts) A single word or two that appear(s) 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. Copyright reserved Please turn over

Downloaded from hlayiso.com 4 LIFE SCIENCES P2 (EC/NOVEMBER 2020) SECTION A QUESTION 1 1.1 1.1.1 B  1.1.2 B  1.1.3 C  1.1.4 A  1.1.5 D  1.1.6 B  1.1.7 C  1.1.8 C  1.1.9 C  9x2 (18) 1.2 1.2.1 mutualism  1.2.2 yeast  1.2.3 phylogenetic tree / cladogram 1.2.4 cones  1.2.5 eutrophication  1.2.6 biodiversity  1.2.7 competitive exclusion  1.2.8 methane  8x1 (8) 1.3 1.3.1 none  1.3.2 A only  1.3.3 B only  3x2 (6) 1.4 1.4.1 Plantae  (1) 1.4.2 Bryophytes  (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2020) LIFE SCIENCES P2 5 1.4.3 B D (Mark first TWO only) (2) 1.4.4 Diagram 3  (Mark first ONE only) (2) 1.4.5 Diagram 3  (Mark first ONE only) (2) 1.5 1.5.1 (a) exponential growth /accelerating/geometric/logarithmic (1) (b) decelerating phase  (1) (c) death phase / extinction phase (1) 1.5.2 Logistic growth  form (1) 1.5.3 Graph 2  (1) 1.5.4 (a) D (1) (b) B (1) 1.5.5 Environmental resistance  (1) 1.5.6 Population must adapt to their new environment  The population is small  Organisms need to become sexually mature  Organisms need to find mates  (Any 2) (2) TOTAL SECTION A: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com 6 LIFE SCIENCES P2 (EC/NOVEMBER 2020) QUESTION 2 2.1 2.1.1 A – Protein coat  B – RNA  (2) 2.1.2 Antibiotics are used to kill living organisms  Viruses are not living  (2) 2.1.3 A person is given a weak strain of the germ  the body will produce antibodies to fight the infection  The antibodies will protect them against a new / stronger infection of the same germ  (3) 2.1.4 The vaccine would need to go through trial  to ensure it has no negative effects  (2) 2.2 2.2.1 Plasmodium  (1) 2.2.2 mosquito / anopheles (1) 2.2.3 headache  fever  sweating  chills  muscular pain  abdominal pain  diarrhoea  nausea and vomiting  loss of appetite  cough  (Mark first TWO only) (Any 2) (2) 2.2.4 Prevent getting bitten by mosquitoes / (or any example) Get rid of mosquitoes /(or any example) (2) 2.3 2.3.1 Plantae  (1) 2.3.2 U – corolla  V – calyx  (2) 2.3.3 (a) R  ovary  (2) (b) S  anther  (2) 2.3.4 Insects  (or example of an insect)/ wind / self-pollinated (1) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2020) LIFE SCIENCES P2 7 2.3.5 (a) Produces large amounts of food / easier farming as same treatment is given to whole crop (1) (b) A pest population will increase rapidly and destroy the entire crop  / increase in amount of pesticides used (1) 2.3.6 - Crops could be wiped out/attacked by disease if they are all of the same variety.  - Seed banks may store variations of crops that may be hardier to the disease and can replace those wiped out.  - A seed bank stores unusual or rare varieties that are not commercially farmed  to maintain biodiversity  - A seed bank keeps cultures of plants that are not usually grown from seed  in case they are needed to replace plants that go extinct in the wild  - Endemic species need to be preserved  as they do not occur elsewhere in the world  - Endangered species may be preserved  In case they go extinct in the wild  - Species may have the potential to provide us with substances of medicinal value  - They must be preserved so that they can be studied before they go extinct.  (Mark first TWO only) (Any 2 x 2) (4) 2.3.7 asexual  (1) 2.3.8 - Crop grows faster than from a seed  therefore can produce potatoes in shorter time  - Do not have to wait to see if seed germinates  as potato tubers are already germinating  (Mark first ONE only) (Any 1 x 2) (2) 2.4 2.4.1 Cnidaria  (1) 2.4.2 radial  (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 LIFE SCIENCES P2 (EC/NOVEMBER 2020) 2.4.3  Mark allocation: Heading  Correct drawing Labels  Drawing   Body Plan of Cnidaria showing tissue layers  (4) 2.4.4 They are radially symmetrical,  therefore they can sense food/ danger equally well in all directions  (2) 2.5 2.5.1 Yes  (1) 2.5.2 It has a brain  (1) 2.5.3 The body wall can work independently  from the gut wall  (2) 2.5.4 Due to separation of body wall and gut wall /coelom diffusion is inadequate for transportation of food / waste / gases (2) 2.5.5 - They eat decomposed/dead organic (plant) material. / Faeces of earthworms are rich in nutrients for plants and enrich the soil  - They aerate the soil /create underground tunnels This helps to infiltrate the soil with water  and helps the plants to grow their roots deeper (4) [50] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2020) LIFE SCIENCES P2 9 QUESTION 3 3.1 3.1.1 They can capture prey too fast for them  and they can tackle prey too large for them  (2) 3.1.2 predation / predator-prey (1) 3.1.3 A (1) 3.1.4 - Graph A increases / decreases after graph B  - There are fewer individuals in A than B  - There is less fluctuation in numbers in A than in B (Any 2) (2) 3.1.5 Drought  Flood  (Any relevant factor but NOT tsunami / earthquake / hurricane) (Mark first ONE only) (1) 3.1.6 Large numbers mean that an individual is less likely to be caught by a predator / prey have a better opportunity to escape. As there are many eyes to spot the predator early / as running in herds may reduce the ability of a predator to focus on one individual to attack (2) 3.1.7 If the prey numbers increase the predator numbers will increase  Causing the prey numbers to decrease  which will cause the predator numbers to decrease  OR The predator and prey numbers depend on each other  This helps to control the population size in each group  If one increases, the other one will cause it to decrease again  (3) 3.2 3.2.1 (a) The increase in the average temperature on earth  (1) (b) The access to enough  nutritious  food, at all times,  by all people  (Any 3) (3) 3.2.2 carbon dioxide  (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 10 LIFE SCIENCES P2 (EC/NOVEMBER 2020) 3.2.3 - Changes in rainfall patterns  cause - desertification / increased flooding / wildfires  - which increase soil erosion  resulting in - fewer crops to be planted / lower crop yield  - there will be less food for livestock  - Higher environmental temperatures negatively affect livestock / crops - These factors decrease food availability / increase food prices (Any 5) (5) 3.3 3.3.1 (a) Invasive alien species  (1) (b) Water consumption  Area invaded by plants  (2) 3.3.2 Quadrat / simple sampling (1) 3.3.3 (2550 m3/ hectare x 752 hectares)  = 1 917 600  m3  (3) 3.3.4 Graph showing water consumption of various Invasive Alien Species in the Olifants River catchment 3000 Water consumption (m3 / hectare) 2550 2500 2000 1500 1250 1155 1000 830 645 500 0 Invasive Alien Species Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/NOVEMBER 2020) LIFE SCIENCES P2 11 Marking guideline: Caption (C) 1 Mark Both variables included Type of graph (T) 1 Mark X-axis label, bars of equal width (X) 1 Mark Y-axis label and scale (Y) 1 Mark Plotting of points (P) 0 Mark – No points plotted correctly 1 Mark – 1 to 6 points plotted correctly 2 Marks – all points plotted correctly (6) 3.3.5 Biological control / example Chemical control / example Mechanical control /example (3) 3.3.6 Do not plant exotic plants in your garden  Remove exotic plants from your garden  Form a hacking club to chop down alien trees  (Mark first ONE only) (Any 1) (1) 3.4 3.4.1 The total count of all the individuals in a population  (1) 3.4.2 Females  (1) 3.4.3 (a) 1990  (1) (b) 1990  (1) 3.4.4 - There is a decrease in birth rate  due to better education / access to birth control / improved lifestyle with fewer children / better employment opportunities for women - There is an increase in life expectancy  due to better health care available  (Mark first TWO only) (Any 2 x 2) (4) Copyright reserved Please turn over

Downloaded from hlayiso.com 12 LIFE SCIENCES P2 (EC/NOVEMBER 2020) 3.4.5 Useful for planning: - health care  - social welfare  - education  - creating employment  - provision of resources  - housing needs  (Mark first THREE only) (Any 3) (3) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over