Life Sciences Grade 11 P1 Eastern Cape November 2025 Memo

NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2025 LIFE SCIENCES P1 MARKING GUIDELINE MARKS: 150 This marking guideline consists of 10 pages.

2 LIFE SCIENCES P1 (EC/NOVEMBER 2025) 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 a 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 provincial 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

(EC/NOVEMBER 2025) LIFE SCIENCES P1 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

4 LIFE SCIENCES P1 (EC/NOVEMBER 2025) SECTION A QUESTION 1 1.1 1.1.1 A  1.1.2 C  1.1.3 D  1.1.4 D  1.1.5 C  1.1.6 C  1.1.7 D  1.1.8 B  1.1.9 A  1.1.10 C  (10 x 2) (20) 1.2 1.2.1 Breathing / Ventilation 1.2.2 Aldosterone  1.2.3 Pre-molars/Molars  1.2.4 Pharynx  1.2.5 Secretion  1.2.6 Chyme  1.2.7 Distal convoluted tubule  1.2.8 Osmosis  (8) 1.3 1.3.1 A ONLY  1.3.2 B ONLY  1.3.3 NONE  1.3.4 NONE  (8) 1.4 1.4.1 (a) F  – Renal calyx  (2) (b) B  – Renal capsule  (2) (c) C  – Renal pelvis  (2) 1.4.2 Part D is darker because it contains more blood vessels. OR Part A is lighter because it has fewer blood vessels. (1) 1.5 1.5.1 - The body’s ability to maintain a stable internal environment  - despite changes in the external environment  (2) 1.5.2 (a) Chemoreceptors of the carotid artery  (1) (b) Intercostal muscles,  diaphragm  (respiratory muscles ), heart  (Any 2 x 1) (2) 1.5.3 - The blood becomes increasingly acidic  /cell death - Less aerobic respiration can take place  /no ATP created (2) [50] TOTAL SECTION A: 50 Copyright reserved Please turn over

(EC/NOVEMBER 2025) LIFE SCIENCES P1 5 QUESTION 2 2.1 2.1.1 Chloroplast  (1) 2.1.2 - Presence of thylakoid/grana/inter-grana disks/lamellae  - Stroma present  - Starch granules present  (FIRST TWO ONLY) (MAX 2) (Do not accept double membrane as it is not a distinct identifying characteristic as many organelles have this.) (2) 2.1.3 Light (dependent) Phase/B Dark (light-independent) Phase/A Requires light Does not require light Photolysis occurs No photolysis occurs CO2 is not absorbed CO2 is absorbed No glucose is produced Glucose is produced (FIRST TWO ONLY)  per correct difference (MAX 4) + Table  NOTE: Differences must match correctly to be awarded marks. (5) 2.1.4 - Produces food for heterotrophic organisms/Forms basis of food chains  - Production of oxygen  - Absorption and storage of carbon dioxide  - Maintaining/balancing a constant level of oxygen in the environment (aquatic/terrestrial)  (MARK FIRST TWO ONLY) (2) 2.1.5 - Presence of many grana/thylakoids/lamella  It holds a significant amount of chlorophyll (pigment) to maximise that rate of photosynthesis  - Large surface area  To maximise the amount of radiant energy which can enter it - It has a (fluid)stroma  Allowing for chemical reactions to take place/products of the light phase can move into the dark phase  (MARK FIRST ONE ONLY) (1 x 2) (2) Copyright reserved Please turn over

6 LIFE SCIENCES P1 (EC/NOVEMBER 2025) 2.2 2.2.1 - Greenhouses create jobs in rural areas and support the local economy.  - Greenhouses help grow local vegetables, so people don’t have to import food.  - Greenhouses allow farmers to grow crops all year, even when it’s cold.  (MARK FIRST ONE ONLY) (1) 2.2.2 - Greenhouses use geothermal and solar energy,  which reduces the need to use electricity from the local power grid and helps save costs.  (2) 2.2.3 (a) - Use of heaters  powered by geothermal energy. - Insulated material  (like double walls or plastic layers) to keep the heat inside the greenhouse (MARK FIRST TWO ONLY) (2) (b) −25−28  x 100  = 212 % change −25 OR 28−(−25)  x 100  = 212 % change (3) 25 2.2.4 (a) - As light intensity increases, the rate of photosynthesis increases/light intensity is directly proportional to rate of photosynthesis  - Up to a point  - Beyond this point, further increases to light intensity do not affect the rate of photosynthesis  (3) (b) - Chlorophyll is saturated/insufficient  - Not enough enzymes/transfer chains to assist with photosynthesis  (MARK FIRST ONE ONLY) (2) 2.3 2.3.1 (a) Glycolysis (1) (b) Oxygen (1) (c) Carbon dioxide (1) 2.3.2 - Catabolic * Glucose is broken down into pyruvic acid  OR A six-carbon glucose molecule is broken to form two three-carbon chain pyruvic acid molecules  (Compulsory * + ANY OTHER ) (2) Copyright reserved Please turn over

(EC/NOVEMBER 2025) LIFE SCIENCES P1 7 2.3.3 - B * Because oxygen is used  as the final electron acceptor, allowing the chain to function continuously OR The process drives the production of about 36 ATP molecules, while glycolysis only produces 2 ATPs  (2) 2.3.4 - Can only take place if oxygen is present  - Occurs inside of the mitochondrion  - Releases carbon dioxide and high energy hydrogen ions (H+)  - Transports hydrogen atoms to the third stage  (4) 2.3.5 - Not enough oxygen was available  to his muscles to undergo aerobic respiration - Pyruvic acid was converted into lactic acid/Lactic acid fermentation occurred  - Lactic acid caused his muscles to cramp  (3) 2.4 2.4.1 Carbon dioxide concentration  (in arbitrary units) (1) 2.4.2 - Duplicating the experiment with all variables kept the same  - Not including the pondweed and pond snail/independent variables  (2) 2.4.3 - The amount of CO2 released during cellular respiration  - is utilised by the pondweed during photosynthesis  (2) 2.4.4 - Photosynthesis could no longer take place  - as no light was available  (2) 2.4.5 - The environment was anoxic/lacked sufficient O2 * - For cellular respiration to occur  - The water became too acidic to support aquatic life  (* plus any other ) (2) 2.4.6 Photosynthesis and cellular respiration are complementary processes  regulating CO2 concentration in the environment.  OR Photosynthesis removes carbon dioxide  and produces oxygen.  OR When there is no light, photosynthesis stops  and carbon dioxide increases due to respiration.  (2) [50] Copyright reserved Please turn over

8 LIFE SCIENCES P1 (EC/NOVEMBER 2025) QUESTION 3 3.1 3.1.1 (a) Oesophagus  (1) (b) Hepatic portal vein  (1) 3.1.2 - The small intestine is long * Increasing surface area for absorption  - It has circular folds * Increasing surface area for absorption  - It is lined with millions of villi * Increasing surface area for absorption  - It is richly supplied with blood vessels * Allowing for an efficient transport system of nutrients from the gut to the body  - It has smooth muscle tissue (circular and longitudinal) * To efficiently move food and indigestible matter through the gut  - Has a mucus rich layer on its surface * To allow for nutrients to dissolve into and to be absorbed into the body  / to lubricate / act as a medium for chemical reactions (MARK FIRST THREE ONLY) (* compulsory mark) (3 x 2) (6) 3.1.3 Physical digestion - Occurs due to the churning movements  of the stomach. - Smooth muscle layers involuntarily contract, mixing the bolus of food with gastric juices  Chemical digestion - occurs as gastric juices/enzymes react with exposed surface  of bolus/chyme - Breaking insoluble macroscopic molecules into their soluble forms / (accept suitable example). (4) 3.1.4 - Bile is produced by the liver  - Bile will still enter the duodenum and fat emulsification will take place  (2) 3.2 3.2.1 - Digestion * - Proteases  (2) 3.2.2 Stomach  (1) 3.2.3 Assimilation  (1) 3.2.4 - Egestion * - Undigested materials and waste products are transported through the colon  where most water and mineral salts are absorbed  - Undigested material is temporarily stored in the rectum  until it is excreted through the anus  (* COMPULSORY + ANY OTHER TWO) (3) Copyright reserved Please turn over

(EC/NOVEMBER 2025) LIFE SCIENCES P1 9 3.3 3.3.1 Breaking of larger food pieces into smaller pieces  making it easier to swallow increases the surface area of the food so that digestive enzymes can work more effectively.  (2) 3.3.2 - Bread contains starch. - During chewing, an enzyme in saliva called amylase breaks down starch  into sugar (maltose),  which tastes sweet. (2) 3.4 3.4.1 Diffusion  (1) 3.4.2 - Mucus layer present inside the alveolus * Allowing for O2 and CO2 to be dissolved as diffusion occurs  - Alveolus is only one squamous epithelium layer thick * Promoting easy diffusion into/out of the wall of the alveolus  - Blood capillary is only one cell layer thick * Promoting easy diffusion into/out the wall of the alveolus  - Richly supplied with blood vessel(s) * Allowing for efficient gaseous exchange (of CO2 and O2) to occur  (ANY TWO * with corresponding reasoning ) (2 x 2) (4) 3.4.3 - As oxyhaemoglobin  - Dissolved within blood plasma  (2) 3.4.4 - Blood would move into the lung/alveoli  Limiting/preventing efficient gaseous exchange  - Pressure would no longer be effectively regulated/ Lung will collapse  Impeding the processes of inhalation and exhalation as pressure is required to pull air into the lung/force air out  - Lung tissue/alveoli/ bronchioles would be damaged  Limiting/preventing gas pathways through the lung  (MAX. 5) (5) 3.5 3.5.1 - ABC (MARK FIRST TWO ONLY) (2) 3.5.2 - Tubular reabsorption * (Useful) solutes and water are moved from the renal tubule back into the peritubular capillary network/F - Tubular secretion * Waste products and toxins are moved from F into the renal tubule  (* with its corresponding ) (4) Copyright reserved Please turn over

10 LIFE SCIENCES P1 (EC/NOVEMBER 2025) 3.5.3 (a) D  - Ascending limb of Henle/loop of Henle  (2) (b) - The renal medulla will no longer be hypertonic in its sodium concentration  - No osmotic water potential gradient would be created  - Between the filtrate/medulla tissue fluid/blood  - Less/no water will be drawn in the renal medulla  - Less water would be reabsorbed back into the blood  (5) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over