Life Sciences Grade 12 P2 NSC November Mock 2026 Memo (Eng)

hlayiso mock exams Practice Series: Grade 12 NSC Preparation WWW.HLAYISO.COM NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P2 MOCK EXAMINATION 2026 MARKING GUIDELINES MARKS: 150 These marking guidelines consist of 11 pages. Copyright reserved Please turn over

Life Sciences/P2 2 Hlayiso/Mock 2026 NSC – Marking Guidelines 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. Copyright reserved Please turn over

Life Sciences/P2 3 Hlayiso/Mock 2026 NSC – Marking Guidelines 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/P2 4 Hlayiso/Mock 2026 NSC – Marking Guidelines SECTION A QUESTION 1 1.1 1.1.1 B✓✓ 1.1.2 C✓✓ 1.1.3 A✓✓ 1.1.4 D✓✓ 1.1.5 B✓✓ 1.1.6 A✓✓ 1.1.7 C✓✓ 1.1.8 D✓✓ 1.1.9 A✓✓ 1.1.10 B✓✓ (10 x 2) (20) 1.2 1.2.1 Transcription✓ 1.2.2 (DNA) replication✓ 1.2.3 Autosomes✓ 1.2.4 Discontinuous variation✓ 1.2.5 (Biological) species✓ 1.2.6 Speciation✓ 1.2.7 Palaeontology✓ 1.2.8 Co-dominance✓ 1.2.9 Pedigree diagram✓ (9 x 1) (9) 1.3 1.3.1 Both A and B✓✓ 1.3.2 A only✓✓ 1.3.3 None✓✓ (3 x 2) (6) 1.4 1.4.1 (a) Metaphase I✓ (1) (b) Metaphase II✓ (1) 1.4.2 (a) B✓ (1) (b) D✓ (1) 1.4.3 (a) Spindle fibre✓ (1) (b) Centromere✓ (1) 1.4.4 4✓ (2n = 4) (1) 1.4.5 2✓ (1) (8) 1.5 1.5.1 (a) Translation✓ (1) (b) tRNA✓/transfer RNA (1) (c) Ribosome✓ (1) 1.5.2 Peptide bond✓ (1) Copyright reserved Please turn over

Life Sciences/P2 5 Hlayiso/Mock 2026 NSC – Marking Guidelines 1.5.3 AGU✓ (1) 1.5.4 CGA✓ (1) 1.5.5 Glycine✓ (1) (7) TOTAL SECTION A: 50 Copyright reserved Please turn over

Life Sciences/P2 6 Hlayiso/Mock 2026 NSC – Marking Guidelines SECTION B QUESTION 2 2.1 2.1.1 (a) Deoxyribose (sugar)✓ (1) (b) Hydrogen bond(s)✓ (1) 2.1.2 (a) Cytosine✓ (1) (b) Thymine✓ (1) 2.1.3 - Nucleus✓ - Mitochondria✓ (Mark first TWO only) (2) 2.1.4 - The double helix (DNA molecule) unwinds✓ - The weak hydrogen bonds between the nitrogenous bases break✓ - and the two strands separate/unzip✓ - Each strand serves as a template✓ - Free DNA nucleotides from the nucleoplasm✓ - attach to the complementary bases✓(A to T and G to C) - Two identical DNA molecules are formed✓, each with one original and one new strand Any 5 (5) 2.1.5 It ensures that the daughter cells that form during cell division receive identical/complete genetic material✓ (1) (12) 2.2 2.2.1 As the age of the mother increases✓, the number of babies born with Down syndrome increases✓(sharply after 35 years) (2) 2.2.2 10,0 ÷ 0,8✓ = 12,5 times✓ (2) 2.2.3 - During meiosis in the ovary, chromosome pair 21/chromatids of chromosome 21 fail to separate✓(non-disjunction) - One ovum receives an extra copy of chromosome 21✓/has 24 chromosomes - This ovum is fertilised by a normal sperm✓with 23 chromosomes - The zygote has 47 chromosomes/three copies of chromosome 21✓(trisomy 21) (4) Copyright reserved Please turn over

Life Sciences/P2 7 Hlayiso/Mock 2026 NSC – Marking Guidelines 2.2.4 Number of babies born with Down syndrome for mothers of different ages 35 Number per 1 000 births 30 25 20 15 10 5 0 20 25 30 35 40 45 Age of mother (years) Criteria Mark Correct type of graph: line graph (T) 1 Caption includes both variables (C) 1 Correct label and unit for X-axis and 1 Y-axis (L) Appropriate scale for X-axis and Y-axis 1 (S) Plotting of points (P): 1–5 points plotted correctly 1 All 6 points plotted correctly 2 If a bar graph or histogram is drawn: marks will be lost for type of graph (T) and scale (S). If the axes are transposed: marks will be lost for labels (L) and scale (S); plotting can still be credited if the points are correct for the labels given. (6) (14) 2.3 2.3.1 Dihybrid cross✓ (1) 2.3.2 rr✓Tt✓ (2) 2.3.3 (a) RrTt✓ (1) (b) rrtt✓ (1) 2.3.4 Red fruit✓and dwarf stem✓ (2) 2.3.5 3 red, tall : 1 red, dwarf : 3 yellow, tall : 1 yellow, dwarf✓✓ (1 mark for the correct phenotypes, 1 mark for the correct ratio) (2) 2.3.6 (Law of) independent assortment✓ (1) (10) 2.4 2.4.1 2✓/Two (1) 2.4.2 XH Y✓ (1) Copyright reserved Please turn over

Life Sciences/P2 8 Hlayiso/Mock 2026 NSC – Marking Guidelines 2.4.3 - Her son, individual 3, has haemophilia/is Xh Y✓ - He inherited the Y-chromosome from his father/individual 1✓ - and the Xh allele from his mother/individual 2✓ - Since she does not have haemophilia she must also have the XH allele/she is XH Xh ✓ Any 3 (3) 2.4.4 50%✓ (1) 2.4.5 P1 Phenotype Normal female x Normal male✓ Genotype XH Xh x XH Y✓ Meiosis G/gametes XH , Xh x XH , Y✓ Fertilisation F1 Genotype XH XH , XH Y, XH Xh , Xh Y✓ Phenotype 2 normal females : 1 normal male : 1 male with haemophilia✓ P1 and F1 ✓ Meiosis and fertilisation✓ Any 6 OR P1 Phenotype Normal female x Normal male✓ Genotype XH Xh x XH Y✓ Meiosis Gametes XH Xh XH XH XH XH Xh Y XH Y Xh Y Fertilisation 1 mark for correct gametes; 1 mark for correct genotypes F1 Phenotype: 2 normal females : 1 normal male : 1 male with haemophilia✓ P1 and F1 ✓; Meiosis and fertilisation✓ Any 6 (6) 2.4.6 - Males have only one X-chromosome✓ - so a single recessive allele (Xh ) will be expressed✓/males cannot be carriers - Females need two recessive alleles to have the disorder✓ Any 2 (2) (14) [50] Copyright reserved Please turn over

Life Sciences/P2 9 Hlayiso/Mock 2026 NSC – Marking Guidelines QUESTION 3 3.1 3.1.1 Percentage of mosquitoes that survived✓ (1) 3.1.2 The percentage of mosquitoes that survived increased✓from 4% in 2014 to 76% in 2022✓/over the eight years (2) 3.1.3 - To make the results comparable/valid✓ - so that any change in survival is due only to the resistance of the mosquitoes✓/and not due to other factors (2) 3.1.4 - There was variation✓in the mosquito population - Some mosquitoes were resistant to the insecticide and others were not✓ - When the insecticide was sprayed, the non-resistant mosquitoes died✓ - The resistant mosquitoes survived✓ - and reproduced✓ - passing on the allele/characteristic for resistance to their offspring✓ - Over many generations the proportion of resistant mosquitoes increased✓ Any 6 (6) 3.1.5 - Use different insecticides in rotation✓ - Use the insecticide only when necessary/reduce spraying✓ - Use other methods such as mosquito nets/removing breeding places✓ Any 1 (Mark first ONE only) (1) (12) 3.2 3.2.1 Allopatric✓/geographic speciation (1) 3.2.2 - The lizard population was split into two populations✓ - by a geographical barrier/the sea✓ - There was no gene flow between the two populations✓ - Each population was exposed to different environmental conditions✓ - Natural selection acted independently on each population✓ - Over many generations the two populations became genetically and phenotypically different✓ - so that they can no longer interbreed✓even if they meet again, forming a new species Any 6 (6) Copyright reserved Please turn over

Life Sciences/P2 10 Hlayiso/Mock 2026 NSC – Marking Guidelines 3.2.3 - Breeding at different times of the year✓ - Species-specific courtship behaviour✓ - Prevention of fertilisation✓/incompatible reproductive structures - Infertile offspring✓ Any 2 (Mark first TWO only) (2) (9) 3.3 3.3.1 SKULL A SKULL B Brow ridges are Brow ridges are less prominent prominent Jaws Jaws do not protrude/flat protrude/prognathous face Cranium is smaller/flatter Cranium is larger/rounded Foramen magnum is Foramen magnum is towards the back more forward/central Large canines Small canines No chin Chin present (Mark first TWO only) Table✓ + any (2 x 2)✓✓✓✓ (5) 3.3.2 - The foramen magnum is more forward/central so the spine is attached vertically below the skull✓ - which allows for an upright posture/bipedalism✓ (2) 3.3.3 - Opposable thumbs✓ - Freely rotating arms✓ - Long upper arms✓ - Bare fingertips/flat nails✓ - Rotating forearms✓/elbow joint allowing rotation Any 2 (Mark first TWO only) (2) (9) 3.4 3.4.1 3✓/Three (1) 3.4.2 Ardipithecus ramidus✓ (1) 3.4.3 Homo erectus✓ (1) Copyright reserved Please turn over

Life Sciences/P2 11 Hlayiso/Mock 2026 NSC – Marking Guidelines 3.4.4 - The oldest hominid fossils (Ardipithecus/Australopithecus) were found only in Africa✓ - The oldest Homo erectus fossils (2,0 mya) were found in Africa✓ - and younger Homo erectus fossils (1,8 mya) were found outside Africa✓, showing that H. erectus migrated out of Africa - The oldest Homo sapiens fossils were found in Africa✓ Any 3 (3) 3.4.5 Mitochondrial DNA✓/mtDNA (1) 3.4.6 It is inherited only from the mother✓/it does not undergo recombination (1) (8) 3.5 3.5.1 Artificial selection✓ (1) 3.5.2 ARTIFICIAL NATURAL SELECTION SELECTION Selection is done by Selection is done by humans nature/the environment Selects for characteristics Selects for characteristics that benefit humans that increase survival Takes place over a Takes place over a long shorter period period Usually results in new May result in the varieties of the same formation of new species species (Mark first TWO only) Table✓ + any (2 x 2)✓✓✓✓ (5) (6) 3.6 3.6.1 Diagram 2✓ (1) 3.6.2 - Long periods of little or no change✓ - alternate with short periods of rapid change✓ - during which new species are formed✓ (3) 3.6.3 - There are gaps in the fossil record/few transitional fossils✓ - which suggests that new species formed rapidly✓/over short periods (2) (6) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved