Life Sciences Grade 12 P1 Gauteng Prelim 2024 Memo (English)

Downloaded from hlayiso.com : AMENDMENT TO MARKING GUIDELINES PREPARATORY EXAMINATIONS – 2024 ATTENTION: THE CHIEF INVIGILATOR SUBJECT / VAK LIFE SCIENCES / LEWENSWETENSKAPPE PAPER / VRAESTEL 1 DATE OF EXAMINATION / DATUM VAN EKSAMEN 6 SEPTEMBER 2024 The errata for the Marking Guidelines of LIFE SCIENCES P1 has reference. There was an anomaly in the manner in which Question 3.4.3 was presented on both the English and Afrikaans versions of the question paper. This matter was addressed at the Marking Standardisation Meeting. To ensure that candidates are not disadvantaged and prejudiced in way, you are advised to please ask your Life Sciences educator(s) to ignore Question 3.4.3 when marking. In other words, the paper must be marked out of a total of 145 instead of 150 and then the learners’ marks must be converted to a mark out of 150. E.g., Should a learner attain 85/145 then that mark is recalculated as 88/150. Use the a b x 100 = b. Then, x 150 = c formula: 145 100 C is the mark that is entered into SASAMS out of 150. 85 88 Please ensure that BOTH marks ( AND ) are reflected on the cover 145 150 page of candidates’ answer scripts. DIRECTOR: EXAMINATIONS MANAGEMENT 6 SEPTEMBER 2024

Downloaded from hlayiso.com Please note, the paper is to be marked out of 145 not 150. USE THE CONVERSION TABLE BELOW 145 – 150 145 150 145 150 145 150 145 150 145 150 1 1 30 31 59 61 88 91 117 121 2 2 31 32 60 62 89 92 118 122 3 3 32 33 61 63 90 93 119 123 4 4 33 34 62 64 91 94 120 124 5 5 34 35 63 65 92 95 121 125 6 6 35 36 64 66 93 96 122 126 7 7 36 37 65 67 94 97 123 127 8 8 37 38 66 68 95 98 124 128 9 9 38 39 67 69 96 99 125 129 10 10 39 40 68 70 97 100 126 130 11 11 40 41 69 71 98 101 127 131 12 12 41 42 70 72 99 102 128 132 13 13 42 43 71 73 100 103 129 133 14 14 43 44 72 74 101 104 130 134 15 15 44 45 73 75 102 105 131 135 15 16 44 46 73 76 102 106 131 136 16 17 45 47 74 77 103 107 132 137 17 18 46 48 75 78 104 108 133 138 18 19 47 49 76 79 105 109 134 139 19 20 48 50 77 80 106 110 135 140 20 21 49 51 78 81 107 111 136 141 21 22 50 52 79 82 108 112 137 142 22 23 51 53 80 83 109 113 138 143 23 24 52 54 81 84 110 114 139 144 24 25 53 55 82 85 111 115 140 145 25 26 54 56 83 86 112 116 141 146 26 27 55 57 84 87 113 117 142 147 27 28 56 58 85 88 114 118 143 148 28 29 57 59 86 89 115 119 144 149 29 30 58 60 87 90 116 120 145 150

Downloaded from hlayiso.com PREPARATORY EXAMINATION 2024 MARKING GUIDELINES LIFE SCIENCES (PAPER 1) (10831) 11 pages

Downloaded from hlayiso.com 10831/24 PRINCIPLES RELATED TO MARKING LIFE SCIENCES 1. 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. 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 the whole process is given when only part of it is required Read all and credit relevant part. 4. If comparisons are asked for and descriptions are given Accept if 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 the 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 the sequence and links become correct again, resume credit. 9. Non-recognised abbreviations Accept if first defined in the answer. If not defined, do not credit the unrecognised abbreviation but credit the rest of the answer if correct. 10. Wrong numbering It is acceptable if the answer fits into the correct sequence of questions, but the wrong number is given. 11. If the language used changes the intended meaning Do not accept. 12. Spelling errors Accept it if recognisable, provided it does not mean something else in Life Sciences or if it is out of context. 4

Downloaded from hlayiso.com 10831/24 13. If common names are given in terminology Accept, provided it was accepted at the memo discussion meeting. 14. If only a letter is asked for and only a name is given (and vice versa) Do not credit. 15. If units are not given in measurements Candidates will lose marks. The memorandum will allocate marks for units separately. 16. Be sensitive to the sense of an answer, which may be stated differently 17. Caption All illustrations (diagrams, graphs, tables, etc.) must have a caption. 18. Code-switching of official languages (terms and concepts) A 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 applies to all official languages. 19. Changes to the markign guidelines No changes must be made to the marking guidelines without consulting the provincial internal moderator. 5

Downloaded from hlayiso.com 10831/24 SECTION A QUESTION 1 1.1 1.1.1 B  1.1.2 A  1.1.3 A orB ✓✓ 1.1.4 C  1.1.5 A  1.1.6 A  1.1.7 B  1.1.8 B  1.1.9 B  1.1.10 A  (10 x 2) (20) 1.2 1.2.1 Thorns /spikes/prickles 1.2.2 Binocular  vision 1.2.3 Prolactin  1.2.4 Astigmatism  1.2.5 Phototropism  1.2.6 Blastocyst/Blastula  (6 x 1) (6) 1.3 1.3.1 B Only  1.3.2 A Only  1.3.3 Both A and B or B only  (3 x 2) (6) 1.4 1.4.1 (a) C  Egg shell/shell ✓ (2) (b) F  Yolk ✓ (2) (c) E  Allantoïs  (2) 1.4.2 (a) (Diagram) A ✓ (1) (b) (Diagram) A  (1) (8) 6

Downloaded from hlayiso.com 10831/24 1.5 1.5.1 (a) Amnion  (1) (b) Uterus /uterus wall (1) (c) Cervix  (1) (d) Foetus  (1) 1.5.2 (a) Vagina  (1) (b) Placenta  (1) (c) Umbilical vein ✓ /umbilical cord (1) 1.5.3 Muscle ✓/myometrium (1) 1.5.4 2, 4, 7, 8  All numbers must be included to earn both marks numbers can be in any order. (2) (10) TOTAL SECTION A: 50 7

Downloaded from hlayiso.com 10831/24 SECTION B QUESTION 2 2.1 2.1.1 (a) 1  – FSH✓/Follicle stimulating hormone (2) (b) 4  – Oestrogen  (2) 2.1.2 (a) – Secretes progesterone ✓ – To maintain the endometrium ✓ (2) (b) – The pituitary gland/hypophysis ✓ – secretes LH ✓/luteinising hormone – which stimulates the conversion of the ruptured Graafian follicle ✓ into the corpus luteum (3) 2.1.3 – The corpus luteum/structure 3 is getting smaller ✓/degenerating – Progesterone/hormone 5 levels are dropping ✓/decreasing – FSH/hormone 1 levels are increasing on days 27 – 28 ✓ (Mark first TWO only) (2) (11) 2.2 2.2.1 (a) Vas deferens  (1) (b) Penis  (1) 2.2.2 – Protection of testes ✓ – Because they are held outside the body ✓ OR – Holds the testes outside of the body ✓ – to ensure they are at a lower temperature for optimum/healthy sperm cell production ✓ (2) 2.2.3 Spermatogenesis * − Under the influence of testosterone ✓ − diploid cells in the seminiferous tubules ✓ of the testes undergo meiosis ✓ − to form haploid sperm cells ✓ * compulsory mark and any THREE points (4) 8

Downloaded from hlayiso.com 10831/24 2.2.4 Diagram of a sperm cell Tail Middle piece/neck Head mitochondria nucleus acrosome The caption must include sperm cell C (1) The diagram contains a head with an acrosome and D (1) nucleus, a middle piece and a tail The correct proportion of the head, middle portion and P (1) tail Labels: any two correct labels L  (2) TOTAL: 5 (5) 2.2.5 Epididymis → vas deferens /Sperm duct → urethra  If the word testes is mentioned, no marks to be awarded (2) (15) 2.3 2.3.1 Gibberellins  (1) 2.3.2 − Same height of corn seedling/All initial heights were 1 cm − Same species were used − Same number of seedlings in each sample − Same amount of water was given − Same amount of hormone mixture in water/1,00 micrograms of hormone − Same period of 15 days for the experiment (Mark first TWO) (Do not accept same environmental conditions) (2) 2.3.3 − Promotes dormancy of seeds ✓/inhibits germination of seeds − Inhibits growth of apical buds ✓ − Induces flowering in some plants ✓ − Promotes ageing of leaves ✓ − Stimulates the abscission/falling of leaves / fruit ✓ − Stimulates closing of stomata ✓ Any TWO (2) 9

Downloaded from hlayiso.com 10831/24 2.3.4 Criteria assessment of the graph CRITERIA ELABORATION SYMBOL MARKS Correct type Bar graph drawn (T) 1 of graph Caption of Both variables included (the (C) 1 graph effect of different hormones on the growth /height of corn seedlings) Axes labels Correct label and unit for X- and (L) 1 Y-axes Scale of X- Equal spacing and correct (S) 1 and Y- axes scaling on X- and Y-axes Plotting of 1 – 3 bars plotted accurately (P) 1 points All 4 bars plotted accurately 2 TOTAL: 6 NOTE: If the wrong type of graph is drawn, marks will be lost for “correct type of graph”. (6) (11) 2.4 2.4.1 (a) Vitreous humour  (1) (b) Optic nerve  (1) 2.4.2 ● Transparent  allows light to enter the eye and reach the retina  ● Causes refraction /bends light toward the yellow spot /retina for clear vision ● Both are convex to allow for refraction  (Mark first ONE only) (2) 10

Downloaded from hlayiso.com 10831/24 2.4.3 ● Light stimulates the cones/photorecetor in part G /retina/yellow spot  ● to convert light to impulses  ● Impulses are transmitted via H/optic nerve  ● to the cerebrum  to be interpreted (4) 2.4.4 Table showing structural differences in the eye for near and far vision. Object closer than 6 m Object further than 6 m Ciliary muscle contracts  Ciliary muscle relaxed  Suspensory ligaments become slack/ Suspensory ligaments tighten/ slacken  become taut  Lens more convex  Lens less convex  T  table including column headings Mark first TWO only (5) (13) [50] QUESTION 3 3.1 3.1.1 2,2  hours ✓ (accept between 2,1 and 2,5 hours) (2) 3.1.2 Time it took for the blood alcohol levels to return to normal ✓/Blood alcohol concentration (1) 3.1.3 − To ensure that all participants started the investigation with no alcohol in their blood ✓ − To ensure the validity ✓of the investigation. − To ensure that all participants begin the investigation with the same/zero blood alcohol concentration ✓ − To allow enough time for blood alcohol concentration to reach zero ✓ (Mark first TWO only) (2) 3.1.4 (a) − Ensure that no participant is pregnant or breastfeeding ✓ − Ensure the participants are not allergic to alcohol ✓/no adverse reactions to alcohol − Ensure participants do not drive ✓/operate heavy machinery/engage in activities that require concentration during and after the investigation (Mark first TWO only) (2) 11

Downloaded from hlayiso.com 10831/24 (b) − Ask participants for permission to be part of the investigation ✓ − Decide how many participants to include ✓ − Decide on the age of participants ✓ − Decide on the weight of participants ✓ − Decide on the volumes of alcohol to be consumed ✓ − Decide on equipment✓/how to monitor blood alcohol concentration − Decide on a suitable venue for the investigation ✓ − Decide on how to record data ✓ − Decide on a time to do the investigation ✓ − Ensure participants do not have a history of alcohol abuse ✓ (Mark first TWO only) (2) 3.1.5 (a) No  (1) (b) − Only 1 participant per volume of alcohol ✓✓ − The investigation was not repeated ✓✓ (Mark first ONE only) (2) 3.1.6 The higher the volume of alcohol consumed the longer it takes to reduce blood alcohol concentration ✓✓ (2) (14) 3.2 3.2.1 (a) Tympanic membrane  (1) (b) Cochlea /organ of Corti (1) (c) Eustachian tube ✓ (1) (d) Auditory canal ✓ (1) 3.2.2 ● The AirPods block the auditory canal  and prevent the sound waves from the environment from reaching the tympanic membrane  ● The sound from the AirPods is too loud  and the environmental noise is too quiet/soft by comparison, so it is not detected  (Each point must have a linked cause and effect statement.) (4) 3.2.3 (a) Fred  (1) (b) (Fred’s) volume is 92 dB /over 80 dB Which is more than the safe level  of 80 dB (2) (11) 3.3 3.3.1 (a) Aldosterone  and adrenalin  (2) (b) Testosterone  (1) 3.3.2 Pituitary gland ✓*/hypophysis is stimulated  To secrete less TSH into the blood  Low TSH levels stimulates the thyroid gland  to secrete less thyroxin  Thyroxin levels decrease / normal *  Compulsory mark and FOUR other points (5) (8) 12

Downloaded from hlayiso.com 10831/24 3.4 3.4.1 (a) Insulin  (b) Blood sugar level starts decreasing  (2) 3.4.2 − Maintenance of a constant internal environment within the body ✓ − Regardless of changes in the internal or external environment ✓ (2) 3.4.3 QUESTION REMOVED, THE PAPER WILL BE MARKED OUT OF 145 (5) (4) 3.5 3.5.1 Hypothalamus  (1) 3.5.2 • the body temperature decreases because • Blood vessels of the skin dilate /vasodilation • More blood flows to the surface of the skin  • More heat is lost from the surface of the skin  • More blood flows to the sweat glands  • to release more sweat /to become more active • Evaporation of sweat cools the skin MARK ANY (5) 3.5.3 Increase in cellular respiration ✓ in muscles produces more energy ✓as heat (2) (8) [45] TOTAL SECTION B: 95 TOTAL: 145 ADDENDUM question Accept 1.2.2 Stereoscopic / 3D vision 1.5.1 (a) Amniotic sac 1.5.1 (b) Uterine wall 2.1.2 (a) To maintain the endometrium ✓/further thicken the endometrium 2.2.1 (a) Sperm duct 2.2.2 20 C lower than body temperature /35oC 2.2.5 If learners included outside penis /into vagina after the urethra they can be awarded the marks. 2.3.2 The word SAME must be included in the answers to award mark 13