Life Sciences Grade 12 P1 Eastern Cape Mock 2023 Memo (Eng)

NATIONAL SENIOR CERTIFICATE SENIOR SERTIFIKAAT GRADE 12 SEPTEMBER 2023 LIFE SCIENCES P1 MARKING GUIDELINE MARKS: 150 This marking guideline consists of 11 pages.

2 LIFE SCIENCES P1 (EC/SEPTEMBER 2023) 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 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 the 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. Copyright reserved Please turn over

(EC/SEPTEMBER 2023) LIFE SCIENCES P1 3 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. 18. Code-switching of official languages (terms and concepts) A single word or two that appear(s) in any official language other than the learner’s 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

4 LIFE SCIENCES P1 (EC/SEPTEMBER 2023) SECTION A QUESTION 1 1.1 1.1.1 C ✓✓ 1.1.2 D ✓✓ 1.1.3 B ✓✓ 1.1.4 A ✓✓ 1.1.5 B ✓✓ 1.1.6 C ✓✓ 1.1.7 B ✓✓ 1.1.8 A ✓✓ 1.1.9 B ✓✓ (9 x 2) (18) 1.2 1.2.1 Epididymis ✓ 1.2.2 Menstrual cycle ✓ 1.2.3 Fallopian tube ✓ 1.2.4 Blastula / Blastocyst 1.2.5 Receptor ✓ 1.2.6 Aqueous humour ✓ 1.2.7 Hair cells/ organ of Corti ✓ 1.2.8 Medulla oblongata ✓ 1.2.9 Islets of Langerhans ✓ (9 x 1) (9) 1.3 1.3.1 None ✓✓ 1.3.2 Both A and B ✓✓ 1.3.3 B only ✓✓ (3 x 2) (6) 1.4 1.4.1 Thermoregulation  (1) 1.4.2 (a) Vasoconstriction  (1) (b) Vasodilation  (1) 1.4.3 (a) B  – Hypothalamus  (2) (b) E – Sweat gland  (2) 1.4.4 - The sweat evaporates  on the surface of skin and - cools down  the body (2) 1.5 1.5.1 Cell body  (1) 1.5.2 (a) Dendrite  (1) (b) Axon  (1) 1.5.3 Sensory neuron  (1) 1.5.4 Interneuron  (1) Copyright reserved Please turn over

(EC/SEPTEMBER 2023) LIFE SCIENCES P1 5 1.5.5 (a) Deterioration of myelin sheath  (1) (b) Extremely slow  transmission of impulses (1) (c) Multiple Sclerosis  (1) TOTAL SECTION A: 50 Copyright reserved Please turn over

6 LIFE SCIENCES P1 (EC/SEPTEMBER 2023) SECTION B QUESTION 2 2.1 2.1.1 (a) Vagina  (1) (b) Menstruation  (1) 2.1.2 Progesterone  (1) 2.1.3 - The Graafian follicle  secretes the - hormone oestrogen  which - makes the uterine lining spongy /thick - so that the embryo can easily implant  - The uterine lining is more vascular /blood rich - so that oxygen/nutrients can be brought to the embryo /more CO2/waste can be taken away  (Any 6 x 1) (6) 2.2 The high concentration of progesterone in the blood: - Inhibits the secretion of FSH  - by the pituitary gland /hypophysis therefore, - no follicle will develop to form Graafian follicle  - resulting in no ovulation / release of ovum (Any 4 x 1) (4) 2.3 - Diploid cells in the ovary undergo mitosis  - to form numerous follicles  - Under the influence of FSH  - Of the four cells that are produced, only one survives to form a mature, haploid ovum  one cell inside a follicle enlarges and undergoes meiosis  (Any 5 x 1) (5) 2.4 2.4.1 (a) Evenly distributed  at the tip (1) (b) Evenly distributed  at the tip (1) 2.4.2 - To cancel the effect (influence) of light  stimuli on the direction of growth therefore, - only gravity  influences the direction of growth (Mark first ONE only) (2) Copyright reserved Please turn over

(EC/SEPTEMBER 2023) LIFE SCIENCES P1 7 2.4.3 Marking guidelines Diagram showing the direction of growth of the young stem and root after a week   Marking criteria Marks Caption 1 Young shoot bending upwards from the horizontally placed position 1 Young root bending downwards from the horizontally placed position 1 (3) 2.4.4 - When the root is placed horizontally  - auxins move to the lower side  - due to gravity  - The high concentration of auxins on the lower side inhibits growth  on the lower side - The lower concentration of auxins on the upper side stimulates growth  in the upper side - The upper side grows faster /uneven growth takes place - causing the root to bend downwards /grow toward gravity (7) 2.5 2.5.1 Adrenal  gland (1) 2.5.2 Endocrine  system (1) 2.5.3 (a) - The level of aldosterone will be very low  because - the high concentration of salt in the blood  - inhibits the adrenal gland  and cause it - to secrete less aldosterone  (Any 3 x 1) (3) (b) - The concentration of salt in the urine will increase  - due to less water being reabsorbed  (2) Copyright reserved Please turn over

8 LIFE SCIENCES P1 (EC/SEPTEMBER 2023) 2.6 2.6.1 (a) Duration of exposure to cellphone radiation  (1) (b) Sperm count  (1) 2.6.2 6 /Six times a year (1) 2.6.3 - 100 volunteers were used  - Semen samples were tested 6 times a year  (Mark first ONE only) (Any 1 x 1) (1) 2.6.4 Same: - Age  - Health  status/ BMI - Diet  - Activity  - Lifestyle  - Person measuring sperm count  (Mark first THREE only) (Any 3 x 1) (3) 2.6.5 - The longer/shorter the duration of exposure to cellphone radiation the lower/higher the average sperm count.  (2) 2.6.7 - The loose under-garments allow the scrotum to move away from the body if the body temperature rises  - since spermatogenesis requires a temperature that is lower than the body temperature to produce normal healthy sperm  (2) [50] Copyright reserved Please turn over

(EC/SEPTEMBER 2023) LIFE SCIENCES P1 9 QUESTION 3 3.1 3.1.1 A (1) 3.1.2 - The receptors in the skin receive the stimulus  and - convert it to a nerve impulse  - the sensory neuron  conducts/ transmits the nerve impulse - to interneuron  in the spinal cord and it transmits the impulses to - the motor neuron  which directs it to the relevant muscle (effector). - the muscle contracts  to pull the foot away quickly (Any 5 x 1) (5) 3.1.3 (a) D (1) (b) B (1) (c) C (1) (d) A (1) 3.2 3.2.1 Absorbs excess pressure waves / releases pressure from the inner ear/ from the inner ear/ prevents an echo (1) 3.2.2 - Vibrations are transmitted to ear ossicles  and this causes - ossicles to amplify  - and transmit the vibrations to oval window  and its vibrations - cause pressure waves  - in the fluid filled cochlea  and this - stimulates hair cells  (organ of Corti) that - convert the stimulus into impulses  - Impulses are transmitted to cerebrum  - through auditory nerve  (Any 7 x 1) (7) 3.2.3 Pharynx /throat (1) 3.2.4 - When the pressure in the outer ear increases  - air moves through the Eustachian tube  into the middle ear - to equalise the pressure on the either side of the tympanic membrane  - to prevent it from bursting  (4) 3.3 3.3.1 A (1) 3.3.2 - Eyes closed - Unable to move/fly/walk - No down feathers (Mark first ONE only) (Any 1 x 1) (1) Copyright reserved Please turn over

10 LIFE SCIENCES P1 (EC/SEPTEMBER 2023) 3.3.3 - Able to move  so that they can avoid being captured by predators /find food - Eyes are open  so that they can locate the food sources/avoid predators in advance  - Have down feathers  to keep them warm  - Have ability to find food sources /feed themselves  to survive independent of parents  (Mark first THREE only) (Any 3 x 2) (6) 3.4 3.4.1 Lens  (1) 3.4.2 - The eyeball is too long  - The lens is too convex / inability of the lens of the eye to become flat(less convex) (2) 3.4.3 - Unable to see distant objects,  but - able to see near objects / able see objects less than 6 m from the eyes. (2) 3.4.4 Concave lens  (1) Copyright reserved Please turn over

(EC/SEPTEMBER 2023) LIFE SCIENCES P1 11 3.4.5 PERCENTAGE CHILDREN WITH SHORT-SIGHTEDNESS AMONGST THE 12-YEAR-OLD CHILDREN IN DIFFERENT 70 PARTS OF THE WORLD Children with short-sightedness 60 50 40 (in abirtrary units) 30 20 10 0 Singapore Hong China USA India Kong Country Criteria for marking graph Mark allocation Bar graph is drawn (T) 1 Caption of the graph includes both variables (C) 1 Correct labels on x-axis and y-axis including the unit (L) 1 Correct scale for y-axis Equal spaces between bars and equal width of bars for x-axis (S) 1 Plotting: (P) 1–4 co-ordinates plotted correctly All 5 co-ordinates plotted correctly 2 (6) 3.5 Due to the excessive sweating, and insufficient intake of fluids: - The volume of water in the blood decreases  - Osmoreceptors in the hypothalamus are stimulated  and impulses are sent to pituitary gland  - which secretes more ADH  into the blood causing - walls of distal convoluted tubule and collecting tubule to become more permeable to water  - More water is reabsorbed into the blood capillaries /less urine formed - Water level in the blood increases  / level of water in the blood returns to normal (7) [50] TOTAL SECTION B: 50 GRAND TOTAL: 150 Copyright reserved Please turn over