Life Sciences Grade 12 Paper 1 KZN Prelim 2024 Memo

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P1 PREPARATORY EXAMINATION SEPTEMBER 2024 MARKS: 150 Copyright Reserved Please Turn Over

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Downloaded from hlayiso.com Life Sciences P1 2 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom 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 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 national memo discussion meeting. 14. If only the letter is asked for, but only the name is given (and vice versa) Do not credit. 15. If units are not given in measurements Candidates will lose marks. Memorandum 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. Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. FINAL! com NATIONAL SENIOR CERTIFICATE GRADE 12 LIFE SCIENCES P1 MARKING GUIDELINES PREPARATORY EXAMINATION SEPTEMBER 2024 MARKS: 150 This marking guideline consists of 9 pages. Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 3 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom SECTION A QUESTION 1 1.1 1.1.1 A /D 1.1.2 C  1.1.3 D  1.1.4 A  1.1.5 B  1.1.6 C  1.1.7 D  1.1.8 D  1.1.9 D  1.1.10 No answer (9 x 2) (18) 1.2 1.2.1 Phototropism  1.2.2 Placenta  1.2.3 Urethra  1.2.4 Vivipary  1.2.5 Amniotic  egg 1.2.6 Herbicides  1.2.7 Maculae  1.2.8 Acrosome  (8) 1.3 1.3.1 B only  1.3.2 A only  1.3.3 B only  (3 x 2) (6) Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 4 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom 1.4 1.4.1 (a) P - Epididymis (2) (b) M - Vas deferens (2) (c) O - Scrotum (2) 1.4.2 - Produces sperm cells/ site of spermatogenesis - Produces testosterone (2) (Mark first TWO only) (8) 1.5 1.5.1 (a) Light (1) (b) Gravity (1) 1.5.2 (a) Root (1) (b) Stem (1) 1.5.3 region P (1) 1.5.4 region S (1) 1.5.5 (a) Negative phototropism (1) (b) Negative geotropism (1) (8) SECTION A: 48 Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 5 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom SECTION B QUESTION 2 2.1 2.1.1 (a) Endometrium /uterus (1) (b) Cervix  (1) (c) Ovary  (1) 2.1.2 (a) It is a site of fertilisation  / allows for the passage of an ovum/zygote. (1) (Mark first ONE only) (b) - Used for copulation  - Serves as a passage for the baby during birth  / It’s a birth canal. Any (1) (Mark first ONE only) 2.1.3 - Sperms and ova will not come into contact  - Fertilisation will not happen  - And a person will be infertile  Any (3) 2.1.4 - It is kept within the uterus/inside the mother’s body - Covered by the chorion  OR extra embryonic membranes - and an amnion  - Surrounded by the amniotic fluid - Which serves as shock absorber /prevents mechanical injuries - and prevents dehydration  - Attached to the mother via placenta  - which produces antibodies  - and filters waste  - Progesterone keeps the endometrium thick  - Prevents miscarriage/allows for the attachment of the embryo. Any (5) (13) Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 6 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom 2.2 2.2.1 Testosterone  (1) 2.2.2 - They hang outside the body  - to expose them at a lower temperature  - than the internal body temperature  - that leads to the development of healthy sperms  - and maintains the sperm count Any (4) (5) 2.3 2.3.1 Peripheral nervous system (1) 2.3.2 Brain and spinal cord (2) (Mark first TWO only) 2.3.3 No answer (2) 2.3.4 Cranial and spinal nerves (Mark first TWO only) 2.3.5 - To increase heart rate - Dilates blood vessels of the skeletal muscles - Dilates the pupil - Constrict the blood vessels of the gut and skin - To increase breathing rate - Stimulates the adrenal gland - To produce more adrenalin - Stimulates the secretion of sweat Any (5) (10) 2.4 2.4.1 No answer 2.4.2 - receptors receive a stimulus  - and convert it into an impulse  - which travels via sensory neuron  - to the spinal cord  - the impulse travels through the synapse  - into the interneuron  - which sends it to the motor neuron  - that carry impulse to the effector  - to bring about a rapid response to the stimulus  Any (5) (5) 2.5 2.5.1 Above 80  years / ≥ 80 years (1) 2.5.2 - Muscle weakness  - Difficulty speaking  - Difficulty moving (hands/arms, legs/feet, any appropriate answer) - Visual problems  Any (2) (Mark the FIRST TWO only) Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 7 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom 2.5.3 The risk of myasthenia gravis increases as the age increase  until the age of 59  after that it decreases as the age increases.  (3) 2.5.4 (1293/100 000)  × 12500000  = 161 625  (3) 2.5.5 Prevalence of myasthenia gravis in males of different age groups Number of males with myathenia gravis (per 900 800 700 600 500 400 100 000 people) 300 200 100 0 ≤19 20 – 39 40 – 59 60 – 79 Age groups (years) MARKING CRITERIA CRITERIA ELABORATION Marks Caption of graph (T) Both variables included 1 Correct type of graph (C) Histogram drawn 1 Axes labels (L) X- and Y – axes correctly 1 labelled with units Scale for X- and Y – axes Equal width of bars for x-axis 1 (S) Correct Y-axis Plotting of bars (P) - 1 – 3 correct bars drawn 1 correctly - All 4 required bars drawn 2 correctly (6) (15) [48] Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 8 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom QUESTION 3 3.1 3.1.1 (a) D  and E  (2) (b) B , C  and I  Any (2) (Mark first TWO only) 3.1.2 (a) Controls the amount of light that enters the eye  (1) (b) - Absorbs excess light - Supplies the eye with nutrients and oxygen  Any (1) (c) Equalises air pressure between the middle and outer ear  (1) 3.1.3 (a) - Contains cristae  - Which are stimulated by the change in direction and speed  - And convert the stimulus into an impulse  (3) (b) - Eardrum vibrates  - Causing ossicles to vibrate and amplify vibrations  - This causes vibration of the oval window  - Setting pressure waves on the endolymph  - Which stimulates the organ of Corti  in the cochlea - Organ of Corti converts the stimulus into an impulse  Any (5) [15] 3.2 3.2.1 Hypothalamus (1) 3.2.2 - rapid heart rate - confusion - dry and hot skin Any (2) (Mark first TWO only) 3.2.3 - blood vessels of the skin constrict  / vasoconstriction occurs - less blood flows to the skin surface  - less heat is lost through radiation - less blood flows to the sweat glands  - sweat glands become less active  - less sweat is produced  - less heat is lost through evaporation  / more heat is retained within the body. Any (4) 3.2.4 - High temperature  - Enzymes will denature  in the cells - The rate of metabolism will decrease  (3) (10) Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 9 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom 3.3 3.3.1  Diabetic person Non-diabetic person 1. More increase in glucose 1. Less increase in glucose level level 2. Takes much longer to return 2. Returns to normal much faster to initial level (5) 1 mark for table + any 4 3.3.2 - During exercise carbon dioxide increases  - The receptors in the carotid arteries detect this increase  - A message is sent to the medulla oblongata  - Which send impulses to the breathing muscles  - and the heart - To increase the rate and depth of breathing  - More deoxygenated blood is sent to the lungs  - More carbon dioxide is exhaled  (5) - Carbon dioxide in the blood returns to normal  Any (10) 3.4 3.4.1 No answer 3.4.2 - 50 adults participated  (2) - The investigation was done over a period of 5 days  Any (Mark first TWO only) 3.4.3 - Ask for permission of the participants  - Decide on the sample size  - Decide on the time and venue  - Decide on the duration of the investigation  - Decide on a measuring tool (2) - Decide on a recording method Any (Mark first TWO only) (1) 3.4.4 Kidney 3.4.5 Participants were: - Of different age groups - Different gender - Different health status/not specified whether they had hypopituitarism - Measurements were not taken throughout the day - Diet and liquid intake was not controlled Any (2) (Mark first TWO only) 3.4.6 No answer (7) 3.4.7 No answer [42] TOTAL SECTION B: 90 GRAND TOTAL: 138 Copyright Reserved Please Turn Over

Downloaded from hlayiso.com Life Sciences P1 10 September 2024 Preparatory Examination Downloaded f rom St NSC – anmorephysics. Marking Guidelinecom CONVERSION TABLE Mark Mark added obtained 133 - 138 +12 121 – 132 +11 110 – 120 +10 97 – 109 +9 87 - 96 +8 74 – 86 +7 63 – 73 +6 52 – 62 +5 40 – 51 +4 30 – 39 +3 18 – 29 +2 6 – 17 +1 0-5 +0 Copyright Reserved Please Turn Over