Life Sciences Grade 12 KZN March Test 2025 Memo

KWAZULU-NATAL PROVINCE EDUCATION REPUBLIC OF SOUTH AFRICA NATIONAL SENIOR CERTIFICATE GRADE 12 ; LIFE SCIENCES COMMON ASSESSMENT TASK MARCH 2025 TEST MARKS: 50 This marking guideline consists of 6 pages

Life Sciences Grade 12 Marking guidelines March 2025 2 PRINCIPLES RELATED TO MARKING LIFE SCIENCES MARCH 2025 1. 10. 11. 12. 13. 14. If more information than marks allocated is given Stop marking when maximum marks are reached and put a wavy line and ‘max’ in the right-hand margin. If, for example, three reasons are required and five are given Mark the first three irrespective of whether all or some are correct/incorrect. If whole process is given when only part of it is required Read all and credit relevant part. If comparisons are asked for and descriptions are given Accept if differences / similarities are clear. If tabulation is required but paragraphs are given Candidates will lose marks for not tabulating. If diagrams are given with annotations when descriptions are required Candidates will lose marks If flow charts are given instead of descriptions Candidates will lose marks. If sequence is muddled and links do not make sense Where sequence and links are correct, credit. Where sequence and links is incorrect, do not credit. If sequence and links becomes correct again, resume credit. Non-recognised abbreviations Accept if first defined in answer. If not defined, do not credit the unrecognized abbreviation but credit the rest of answer if correct. Wrong numbering If answer fits into the correct sequence of questions but the wrong number is given, it is acceptable. If language used changes the intended meaning Do not accept. Spelling errors If recognizable accept provided it does not mean something else in Life Sciences or if it is out of context. If common names given in terminology Accept provided it was accepted at the National memo discussion meeting. If only letter is asked for and only name is given (and vice versa) No credit Copyright reserved Please turn over

Life Sciences Grade 12 Marking guidelines March 2025 15. 16. Its 18. 3 If units are not given in measurements Candidates will lose marks. Memorandum will allocate marks for units separately Be sensitive to the sense of an answer, which may be stated in a different way. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption Code-switching of official languages (terms and concepts) A single word or two that appears 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

Life Sciences Grade 12 Marking guidelines 4 SECTION A QUESTION 1 1.1 BYv DY CvvY DvvY Gyo eee. Peacoat ee Rwryos 1.2 1.2.1 Luteinising hormonev/ LH 1.2.2 Non-disjunctionY” 1.2.3 Cytokinesis~ 1.3 1.3.1 AonlyYv 1.3.2 Bonlyvv 1.4.1. (a) Centromerev (b) Chromatidy 1.4.2 (a) Crossing overY (b) Metaphase 1” 14.3 1v SECTION B QUESTION 2 2.1 2.1.1 (a) tRNAVY (b) mRNAY 2.1.2 Translation” 2.1.3 GAAY 2.1.4 - Brings specific amino acidsY - tothe ribosomeY - For the formation of the required protein’ Copyright reserved March 2025 (4 x 2) (3 x 1) (2 x 2) TOTAL SECTION A: Please turn over (8) (3) (4) (1) (1) (1) (1) (1) (5) 20 (1) (1) (1) (1) (3)

Life Sciences Grade 12 Marking guidelines March 2025 5 2.1.5 - Different protein will be formedY - since anticodon GGAv/ DNA triplet GGA - changed to GUAY/ DNA triplet GTA - and amino acid tyrosineY - will be replaced by serinev in a protein OR - Different / same protein will be formedY - Since anticodon GGA will changeY - to anticodon GUAY - Bringing different / same amino acidY Any (3) (10) 2.2 2.2.1 Man2v (1) 2.2.2 - Some(three) black bars of Susan’s DNA profile correspond with that of the motherY - The remaining (two) black bars of Susan’s DNA profile correspond with that of Man 2¥ (2) 2.2.3. DNA of each individual is unique, except in the case of identical twinsY (1) (Mark the first ONE only) 2.2.4 - To identify criminals/ resolve disputes To identify organisms from their remainsv /dead bodies To identify family relationships other than paternity e.g. siblings To diagnose genetic disordersY - To establish matching tissues” /for tissue typing Any (1) (Mark the first ONE only) (5) QUESTION 3 3.1. 3.1.1. Zinc supplementY (1) 3.1.2 50 (healthy) males in each group Y participated in the investigation (1) (Mark the first ONE only) 3.1.3. - Type of zinc supplementY - Concentration of zincv/ Volume of zinc Any (1) (Mark the first ONE only) 3.1.4 - Group B did not receive the zinc supplementY - If testosterone level increases in group A, it will be due to zinc supplementv (2) 3.1.5 639.4 -348.4v = 291V (2) (7) Copyright reserved Please turn over

Life Sciences 3:2). 3.231 3.2.2 3.2.3 3.2.4 3.2.5 Grade 12 Marking guidelines March 2025 6 (a) OestrogenY (b) ProgesteroneY 14v As the structure C / corpus luteum degeneratesv the level of hormone B /progesterone decreasesY¥ - There will be no thickening of the endometriumY - for the implantation / attachment of embryoY No inhibition of pituitary gland from producing FSHY (Mark the first ONE only) TOTAL SECTION B: GRAND TOTAL: Copyright reserved

GRADE 12 Alternatives Q2.1.5 - The codon CCU code for same amino acid/tyrosine as DNA triplet GGAv - The codon CCU changed to codon CAU which code for same amino acid/serine as the DNA triplet GTA’ - Therefore, the amino acid serine will replace tyrosinev - Resulting with the different protein formedv Q2.2.3 - DNA cannot be alteredv Q2.2.4 - Tracing of ancestryyY Q3.1.2 - 100 men divided into two equal groupsY Q3.1.4 - To verify that zinc supplement is the only cause of increasing the level of testosterone in group AY Q3.2.4 - May results in no stimulation of pituitary gland to release more LHY - resulting ovulation not taking placev Q3.2.5 - It will result in the endometrium breaking downv/there will be no further development of the endometrium/endometrium will no longer be maintained. OR - FSH level will increasev - stopping further thickening of endometriumv - Implantation will not take placev