Life Sciences Grade 12 P1 NSC November Prediction 2026 Memo

Copyright reserved Please turn over hlayiso mock exams Practice Series: Grade 12 NSC Preparation WWW.HLAYISO.COM NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P1 PREDICTION EXAMINATION 2026 MARKING GUIDELINES MARKS: 150 These marking guidelines consist of 11 pages.

Life Sciences/P1 2 NSC – Marking Guidelines Hlayiso/Prediction 2026 PRINCIPLES RELATED TO MARKING LIFE SCIENCES 1. If more information than marks allocated is given Stop marking when the maximum marks are reached; draw a wavy line and write ‘max’ in the right-hand margin. 2. If, for example, three reasons are required and five are given Mark the first three only, irrespective of whether they are correct or incorrect. 3. If a whole process is given when only a part of it is required Read all of it 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 lose the mark for the table. 6. If diagrams with annotations are given when descriptions are required Candidates lose marks. 7. If flow charts are given instead of descriptions Candidates lose marks. 8. If the sequence is muddled and links do not make sense Credit where the sequence and links are correct. Where they are incorrect, do not credit. If they become correct again, resume crediting. 9. Non-recognised abbreviations Accept if first defined in the answer; otherwise do not credit the abbreviation but credit the rest of the answer if correct. 10. Wrong numbering If the answer fits into the correct sequence of questions but the wrong number is given, it is acceptable. 11. If the language used changes the intended meaning Do not accept. 12. Spelling errors Accept if recognisable, provided it does not mean something else in Life Sciences and is not out of context. 13. If only the letter is asked for but only the name is given (and vice versa) Do not credit. 14. If units are not given in measurements Candidates lose marks; the marking guidelines allocate marks for units separately. 15. Be sensitive to the sense of an answer, which may be stated in a different way. 16. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption. 17. Code-switching of official languages (terms and concepts) A single word or two in another official language should be credited if it is correct. 18. Symbols used in these marking guidelines ✓= one mark; / = alternative answer; * = compulsory mark; (Mark first … only) = mark only the stated number of answers in the order given. Copyright reserved Please turn over

Life Sciences/P1 3 NSC – Marking Guidelines Hlayiso/Prediction 2026 SECTION A QUESTION 1 1.1 1.1.1 B✓✓ 1.1.2 C✓✓ 1.1.3 D✓✓ 1.1.4 C✓✓ 1.1.5 A✓✓ 1.1.6 B✓✓ 1.1.7 C✓✓ 1.1.8 D✓✓ 1.1.9 A✓✓ 1.1.10 C✓✓ (10 x 2) (20) 1.2 1.2.1 Chorionic villi✓ 1.2.2 Spermatogenesis✓ 1.2.3 Accommodation✓ 1.2.4 Adrenalin✓/epinephrine 1.2.5 Oval window✓ 1.2.6 Corpus callosum✓ 1.2.7 Islets of Langerhans✓ 1.2.8 Phototropism✓/positive phototropism (8 x 1) (8) 1.3 1.3.1 Both A and B✓✓ 1.3.2 A only✓✓ 1.3.3 B only✓✓ (3 x 2) (6) 1.4 1.4.1 (a) Fallopian tube✓/oviduct (1) (b) Endometrium✓ (1) 1.4.2 (a) Ovulation✓ (1) (b) Fertilisation✓ (1) 1.4.3 LH✓/Luteinising hormone (1) 1.4.4 Blastocyst✓/blastula (1) 1.4.5 - It is thick✓ - It is highly vascular/has many blood vessels✓ - It is glandular/secretes nutrients/mucus✓ - It is soft/spongy✓ (Mark first TWO only) Any 2 (2) (8) 1.5 1.5.1 (a) Pituitary gland✓/hypophysis (1) (b) TSH✓/Thyroid stimulating hormone (1) (c) Thyroid gland✓ (1) Copyright reserved Please turn over

Life Sciences/P1 4 NSC – Marking Guidelines Hlayiso/Prediction 2026 1.5.2 Negative feedback✓(mechanism) (1) 1.5.3 - Controls/regulates the metabolic rate/metabolism✓ - Regulates (physical and mental) growth and development✓ - Regulates the release of energy from food/cellular respiration✓ (Mark first ONE only) Any 1 (1) 1.5.4 Goitre✓ (1) 1.5.5 - Iodine is needed to make thyroxin✓ - so the thyroxin level remains low✓ - and the pituitary gland is continuously stimulated/not inhibited✓ - to secrete (more) TSH Any 2 (2) (8) TOTAL SECTION A: 50 Copyright reserved Please turn over

Life Sciences/P1 5 NSC – Marking Guidelines Hlayiso/Prediction 2026 SECTION B QUESTION 2 2.1 2.1.1 Internal✓(fertilisation) (1) 2.1.2 Ovipary✓ (1) 2.1.3 - The (hard) shell✓prevents dehydration/drying out of the embryo✓/protects the embryo against mechanical injury - The shell is porous✓allowing gaseous exchange✓ - The amnion/amniotic fluid✓prevents the embryo from drying out/protects it against shock✓ - The yolk (sac)✓provides food for the embryo✓while it develops away from water - The allantois✓stores nitrogenous waste✓ (Mark first ONE only) Any 1 x 2 (2) 2.1.4 - Fertilisation is internal✓so most eggs are fertilised✓ - The eggs have shells/are buried in a nest✓so the embryos are protected and more survive✓ - Young are precocial/well developed and can feed themselves on hatching✓so more survive✓ - Frogs have external fertilisation✓and many of their eggs are not fertilised or are eaten✓ Any 2 (2) (6) 2.2 2.2.1 (a) Vas deferens✓/sperm duct (1) (b) Cowper’s gland✓/bulbo-urethral gland (1) 2.2.2 (a) G✓– testis✓ (2) (b) F✓– epididymis✓ (2) Mark for the letter only if the name is correct. 2.2.3 (a) - Most of the semen is fluid secreted by the seminal vesicles, prostate gland and Cowper’s glands✓ - These glands are not affected/their secretions enter the urethra beyond the cut✓ (2) (b) - Sperm cannot move from the epididymis/testes to the urethra✓ - so the semen contains no sperm✓ - and no ovum can be fertilised✓ Any 2 (2) Copyright reserved Please turn over

Life Sciences/P1 6 NSC – Marking Guidelines Hlayiso/Prediction 2026 2.2.4 - The testes still produce testosterone✓ - which is secreted directly into the blood✓/does not pass through the vas deferens - so the level of testosterone (which maintains the secondary sexual characteristics) is not affected✓ Any 2 (2) (12) 2.3 2.3.1 Day 21✓ (1) 2.3.2 Corpus luteum✓ (1) 2.3.3 As the progesterone level increases✓the FSH level decreases✓ OR: There is an inverse relationship✓✓between progesterone and FSH (2) 2.3.4 - (High progesterone inhibits FSH so) no new follicles develop✓ - and no further ovulation can take place✓ - so that no new ovum is released while a possible pregnancy is supported✓ Any 2 (2) 2.3.5 14−5 5 ×100✓✓= 180 %✓ Accept readings of 13,9 to 14,1 and 4,9 to 5,1, giving answers from 172,5 % to 187,8 %. Mark the answer consistently with the learner’s own readings. (3) 2.3.6 - The progesterone level would remain high✓* - because the corpus luteum does not degenerate/is maintained✓ - and (later) the placenta secretes progesterone✓ - to maintain the endometrium/prevent menstruation✓ * compulsory mark + Any 2 (3) (12) 2.4 2.4.1 (a) Interneuron✓/connector neuron/association neuron (1) (b) Effector✓/muscle (1) 2.4.2 (a) P✓ (1) (b) S✓ (1) 2.4.3 P →Q →R →T →U✓✓ All five letters in the correct sequence: 2 marks; one letter out of place: 1 mark (2) Copyright reserved Please turn over

Life Sciences/P1 7 NSC – Marking Guidelines Hlayiso/Prediction 2026 2.4.4 - Neuron Q is the sensory neuron✓ - Impulses from the receptor/P cannot be transmitted to the spinal cord✓ - so no impulse reaches the brain/cerebrum✓ - and therefore no pain is felt✓ - No impulse is sent to the interneuron/R and the motor neuron/T✓ - so the effector/muscle/U is not stimulated to contract✓and the hand is not pulled away Any 4 (4) (10) 2.5 2.5.1 As the average screen time per day increases✓the percentage of learners with short-sightedness increases✓ OR: The more time spent looking at screens✓the higher the percentage of short-sighted learners✓ (2) Copyright reserved Please turn over

Life Sciences/P1 8 NSC – Marking Guidelines Hlayiso/Prediction 2026 2.5.2 Less than 1 1 to less than 2 2 to less than 3 3 to 4 More than 4 0 5 10 15 20 25 30 35 40 Average screen time per day (hours) Learners with short-sightedness (%) Percentage of learners with short-sightedness for different screen times Criteria Mark Correct type of graph: bar graph or histogram (T) 1 Caption includes both variables (C) 1 Correct label and unit for X-axis and Y-axis (L) 1 Appropriate scale for Y-axis; bars of equal width (and equally spaced if separate) (S) 1 Plotting of bars (P): 1–4 bars plotted correctly 1 All 5 bars plotted correctly 2 If a line graph is drawn: marks lost for T and S. A histogram (touching bars) is accepted for T; do not penalise S for bars touching. If the axes are transposed: marks will be lost for labels (L) and scale (S); plotting can still be credited if the bars are correct for the labels given. (6) 2.5.3 - The eyeball is too long✓/the lens is too convex/refracts light too much - so light rays from the board/distant objects are focused in front of the retina✓ - and a blurred image forms on the retina✓ Any 2 (2) (10) [50] Copyright reserved Please turn over

Life Sciences/P1 9 NSC – Marking Guidelines Hlayiso/Prediction 2026 QUESTION 3 3.1 3.1.1 (a) Tympanic membrane✓/eardrum (1) (b) Eustachian tube✓ (1) 3.1.2 (a) E✓ (1) (b) F✓ (1) 3.1.3 - When the head is tilted, the maculae✓ - in the sacculus and utriculus✓ - are stimulated (by the pull of gravity on the otoliths/the jelly-like layer)✓ - The stimulus is converted into impulses✓ - which are transmitted via the auditory nerve✓ - to the cerebellum✓ - The cerebellum sends impulses to the skeletal muscles✓ - to restore balance✓ Any 4 (4) 3.1.4 - The air pressure in the middle ear is lower than the pressure in the outer ear/cabin✓ - so the tympanic membrane/A is pushed inwards/is stretched✓and cannot vibrate freely - When the Eustachian tube/C opens, air moves into the middle ear✓ - and the pressure on both sides of the tympanic membrane is equalised✓ - so the tympanic membrane can vibrate normally again✓ Any 3 (3) (11) 3.2 3.2.1 (a) Hypothalamus✓ (1) (b) Medulla oblongata✓ (1) 3.2.2 A✓– cerebrum✓ (2) 3.2.3 - Part E is the cerebellum✓ - which coordinates voluntary movements✓ - and maintains balance✓ - Since it was damaged, she walked unsteadily/her movements were not coordinated✓ - The cerebrum/part A, which controls thinking and speech, was not damaged✓ Any 3 (3) (7) Copyright reserved Please turn over

Life Sciences/P1 10 NSC – Marking Guidelines Hlayiso/Prediction 2026 3.3 3.3.1 B✓ (1) 3.3.2 - The blood glucose level of B was already above normal before drinking the glucose✓/7,6 mmol/ℓat time 0 - The blood glucose level of B rose much higher✓/to 14 mmol/ℓ - The blood glucose level of B did not return to normal✓/remained high after 3 hours (Mark first TWO only) Any 2 (2) 3.3.3 - The increase in the blood glucose level is detected by the pancreas/islets of Langerhans✓ - which secrete insulin✓ - Insulin stimulates the liver and muscles to convert excess glucose to glycogen✓ - and increases the uptake of glucose by body cells✓ - so the blood glucose level decreases to normal✓ Any 4 (4) 3.3.4 - The low glucose level is detected by the pancreas/islets of Langerhans✓ - The pancreas/islets of Langerhans secrete glucagon✓ - Glucagon stimulates the liver to convert glycogen to glucose✓ - The glucose is released into the blood and the level increases to normal✓ Any 3 (3) (10) 3.4 3.4.1 (a) Percentage of carbon dioxide in the inhaled air✓ (1) (b) (Average) breathing rate✓ (1) 3.4.2 - Gender/only males were used✓ - Age/19 to 21 years old✓ - State of health/all healthy✓ - Activity/all sat still✓ - Time breathing each mixture/5 minutes✓ - Time when the breaths were counted/fifth minute✓ - Rest period/15 minutes between trials✓ - The same volunteers were used for each percentage of CO2✓ (Mark first TWO only) Any 2 (2) 3.4.3 - Twelve volunteers were used✓/a large sample - The average breathing rate was calculated✓ (Mark first ONE only) Any 1 (1) 3.4.4 - Obtain (informed) consent from the volunteers✓ - Ensure that the concentrations of carbon dioxide used were safe✓ - Obtain approval from an ethics committee✓ (Mark first ONE only) Any 1 (1) Copyright reserved Please turn over

Life Sciences/P1 11 NSC – Marking Guidelines Hlayiso/Prediction 2026 3.4.5 As the percentage of carbon dioxide in inhaled air increases✓the breathing rate increases✓ OR: The higher the percentage of carbon dioxide in inhaled air, the higher the breathing rate✓✓ (2) 3.4.6 - Receptors in the carotid artery✓ - detect the high carbon dioxide level✓ - and send impulses to the medulla oblongata✓ - The medulla oblongata sends impulses to the breathing muscles/intercostal muscles and diaphragm✓ - which contract more actively/faster✓ - The rate and depth of breathing increase✓ - The heart is also stimulated to beat faster✓ - so that more carbon dioxide is taken to the lungs and exhaled✓ - and the carbon dioxide level returns to normal✓ Any 5 (5) (13) 3.5 3.5.1 Percentage of plants that died✓/number of plants that died (1) 3.5.2 - It acts as a control✓ - to show that the death of the plants was caused by the synthetic auxin✓/to compare the results with (2) 3.5.3 - 200 mg/ℓ✓* - At this concentration all/100 % of the blackjack plants died✓ - and none/0 % of the maize plants died✓ - A higher concentration/400 mg/ℓalso killed some/15 % of the maize plants✓ * compulsory mark + Any 2 (3) 3.5.4 - A high concentration of auxins causes rapid/abnormal/uncontrolled growth✓ - The plant uses up all its food reserves✓/its tissues are damaged - and it dies Any 2 (2) 3.5.5 - It kills only the weeds and not the crop✓ - It is quicker/needs less labour✓/cheaper for large areas - The whole weed (including the roots) is killed so it does not grow again✓ (Mark first ONE only) Any 1 (1) (9) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved