Life Sciences Grade 12 P1 Eastern Cape Mock 2021 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 SEPTEMBER 2021 LIFE SCIENCES P1 MARKING GUIDELINE MARKS: 150 This marking guideline consists of 11 pages.

Downloaded from hlayiso.com 2 LIFE SCIENCES P1 (EC/SEPTEMBER 2021) 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 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

Downloaded from hlayiso.com (EC/SEPTEMBER 202) 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

Downloaded from hlayiso.com 4 LIFE SCIENCES P1 (EC/SEPTEMBER 2021) SECTION A QUESTION 1 1.1 1.1.1 D ✓✓ 1.1.2 A ✓✓ 1.1.3 B ✓✓ 1.1.4 A ✓✓ 1.1.5 A ✓✓ 1.1.6 C ✓✓ 1.1.7 C ✓✓ 1.1.8 A ✓✓ 1.1.9 C ✓✓ 1.1.10 A ✓✓ (10 x 2) (20) 1.2 1.2.1 Meninges ✓ 1.2.2 Peripheral ✓nervous system 1.2.3 Dendrite ✓ 1.2.4 Geotropism ✓ 1.2.5 Round window ✓ 1.2.6 Thyroxin ✓/ adrenalin 1.2.7 Adrenal gland ✓ 1.2.8 Vagina ✓ (8 x 1) (8) 1.3 1.3.1 B only ✓✓ 1.3.2 Both A and B ✓✓ 1.3.3 B only ✓✓ (3 x 2) (6) 1.4 1.4.1 D → C → A ✓✓ (2) 1.4.2 To protect ✓ /minimise injury to the body (1) 1.4.3 - Muscle ✓ - Gland ✓ (Any 1 x 1) (1) (Mark first ONE only) 1.4.4 (a) C ✓ – Interneuron ✓/connector neuron (2) (b) B ✓ – Ventral root ✓ (2) (c) A ✓ – Motor neuron ✓ (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 202) LIFE SCIENCES P1 5 1.5 1.5.1 (a) Thyroid gland ✓ (1) (b) Testes ✓ (1) 1.5.2 (a) Pituitary ✓gland / Hypophysis (1) (b) TSH ✓ / Thyroid stimulating hormone (1) (c) Adrenal gland ✓ (1) 1.5.3 A✓ (1) TOTAL SECTION A: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com 6 LIFE SCIENCES P1 (EC/SEPTEMBER 2021) SECTION B QUESTION 2 2.1 2.1.1 External ✓ fertilisation (1) 2.1.2 - The eggs are fertilised in the external structure ✓ of male (brood pouch) / eggs are not fertilised in the female reproductive tract (1) 2.1.3 - A large number of eggs are deposited ✓ into the pouch in order to increase the chances of fertilisation ✓ - Fertilisation occurs inside the pouch ✓ to increase the chances of fertilisation ✓ - The development of larvae/embryo takes place inside the pouch, ✓ therefore they are protected from predators ✓ / any environmental factors (Any 2 x 2) (4) 2.1.4 - The development of the embryos takes place in the male pouch ✓ In vivipary it takes place in the uterus ✓ - The embryos are nourished by the yolk of the egg ✓ in seahorses In vivipary the embryos are nourished by the placenta ✓ - Fluid secreted inside the pouch facilitates excretion and gaseous exchange ✓ In vivipary the placenta facilitates excretion and gaseous exchange ✓ (Mark first ONE only) (Any 1 x 2) (2) 2.2 2.2.1 Period of development of an embryo ✓✓ / foetus between conception and birth (2) 2.2.2 22 days ✓ (1) 2.2.3 Amount of progesterone ✓ (1) 2.2.4 Same: - Species of rats ✓ - Concentration of progesterone injected ✓ - Type/brand of progesterone ✓ - Level of activity of the rats ✓ - Health condition of rats ✓ - Type of food ✓ (Any 2 x 1) (2) (Mark first TWO only) 2.2.5 - Ovary releases progesterone ✓ therefore, - removal of ovary enables the investigator to administer different amounts of progesterone ✓ - to compare its effect on gestation period ✓ (3) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 202) LIFE SCIENCES P1 7 2.2.6 - The number of rats who completed gestation was divided by the total number of rats in each group ✓ - and multiplied by 100 ✓ (2) 2.2.7 - To serve as a control ✓ - so that it can be compared ✓with the other groups - to determine if progesterone affect the successful completion of gestation ✓ (Any 2 x 1) (2) 2.3 2.3.1 (a) A – Suspensory ligament ✓ (1) (b) B – Iris ✓ (1) 2.3.2 Protects the eye ✓ (1) 2.3.3 - Ciliary muscles relax ✓ - Suspensory ligaments become taut ✓ - Tension on the lens increases ✓ - The lens becomes flattened ✓ / less convex - The refractive power of the lens is decreased ✓ / light rays are bent less - light rays are focused on the retina ✓ - To form a clear image (Any 4 x 1) (4) 2.3.4 - No impulse will be transmitted ✓ - to the cerebrum ✓ - resulting in loss of vision ✓ (3) 2.4 2.4.1 A mechanism that maintains constant internal environment ✓✓ (2) 2.4.2 - (Cold) receptors / thermoreceptors in the skin are stimulated ✓ - to transmit an impulse to the hypothalamus ✓ - the hypothalamus send impulses to the - blood vessels of the skin - and sweat glands ✓ - The blood vessels of the skin constrict ✓ (vasoconstriction) - Less blood flows to the surface of the skin ✓ and - less heat is lost ✓ from the body - Less blood also sent to the sweat glands - less sweat is produced ✓ and - less heat is lost by evaporation ✓ of sweat - The core temperature of the body rises and is maintained (Any 7 x 1) (7) 2.4.3 - Enzymes become inactive ✓ - causing all metabolic processes to stop ✓/ slow down - leading to multiple organ failure ✓/ no respiration / no release of energy (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 LIFE SCIENCES P1 (EC/SEPTEMBER 2021) 2.5 2.5.1. Prostate gland ✓ (1) 2.5.2 Transport semen and urine ✓ (1) 2.5.3 - The testes require 2 ºC less than the temperature of the body ✓ - to produce normal and healthy sperms ✓ - Therefore, on a hot day, the scrotum relaxes in order to pull the testes away from the body ✓ - to avoid direct contact with the body ✓ - to maintain a lower temperature ✓ (Any 3 x 1) (3) 2.5.4 - Only one of the vas deferens was blocked by the surgery ✓ - therefore, semen with sperm was still transported by the other side ✓ / sperms came from the other testis (2) [50] Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 202) LIFE SCIENCES P1 9 QUESTION 3 3.1 3.1.1 Auditory nerve ✓ (1) 3.1.2 Equalises pressure on either side of the tympanic membrane ✓ (1) 3.1.3 (a) Pinna ✓ (1) (b) Organ of Corti ✓ / Cochlea (1) 3.1.4 (a) - The ossicles will not vibrate ✓ - therefore, vibrations will not be transmitted to the oval window ✓ - and pressure waves will not be created in the inner ear ✓/ - Organ of Corti will not be stimulated to generate impulse ✓/ no impulse will be sent to the brain for hearing to occur (Any 3 x 1) (3) (b) - Part D / tympanic membrane will not be able to create vibrations ✓ - No vibrations will be sent to ossicles ✓ / oval window - Therefore, no pressure waves will be created in the inner ear ✓ - Organ of Corti will not be stimulated to generate impulses ✓ / no impulses will be sent to the brain for hearing to occur (Any 3 x 1) (3) 3.1.5 - The cristae are stimulated  - to convert the stimulus into an impulse  - which is transmitted through the auditory nerve  - to the cerebellum  where they are interpreted - The cerebellum send impulse to skeletal muscles  to restore balance (Any 4 x 1) (4) 3.2 3.2.1 (a) - To remove the auxins  produced at the apical bud (1) (b) - To allow the auxins to diffuse into the block of agar ✓ (1) 3.2.2 - The auxin will diffuse into the right side ✓of the stem - There will be high concentration of auxins on the right- side ✓ of the stem - High concentration of auxins will stimulate cell elongation ✓ /growth mainly on the right-side - This uneven growth ✓ - will cause the stem to bend to the left side by bending of stem tip towards the left-hand side ✓* *1 Compulsory + Any 3 (4) Copyright reserved Please turn over

Downloaded from hlayiso.com 10 LIFE SCIENCES P1 (EC/SEPTEMBER 2021) 3.2.3 - The auxin will diffuse to the lighter side ✓ (left-hand side) - and move to the darker side✓ (right hand side) - High concentration of auxins at darker side stimulates cell elongation ✓/ growth than the cells at the lighter side - This uneven growth ✓ - causes the stem to bend to the left side towards lighter side ✓* (left hand side) *1 Compulsory +Any 3 (4) 3.2.4 - More lateral branches develop  increasing the yield  - Fruit will be accessible from the branches enabling easier harvest  (Any 1 x 2) (2) (Mark first ONE only) 3.3 3.3.1 (a) Insulin ✓ (1) (b) Pancreas ✓ (1) 3.3.2 Negative feed-back ✓ mechanism / homeostasis (1) 3.3.3 During fasting no food is consumed therefore - The glucose level drops below normal ✓ - The pancreas will not be stimulated to secrete insulin ✓/less will be secreted / the level of insulin will drop (2) 3.3.4 - When the level of glucose decreases below the normal levels ✓ - the pancreas is stimulated to secrete more glucagon ✓ / hormone B - which stimulates the conversion of glycogen to glucose ✓ - raising the levels of glucose ✓ back to normal (4) 3.4.1 (a) Amniotic fluid ✓ (1) (b) Chorion ✓ (1) 3.4.2 Umbilical vein ✓ (1) 3.4.3 - Serves as an attachment of embryo to the mother ✓ - Allows the diffusion of dissolved food from the mother to the foetus ✓ - Allows the diffusion of oxygen from the mother to the foetus ✓ - Allows for the diffusion of carbon dioxide from the foetus the mother ✓ - Allows for the diffusion of nitrogenous excretory wastes from the foetus to the mother ✓ - It secretes progesterone ✓ which maintains pregnancy (Mark first TWO only) (Any 2 x 1) (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (EC/SEPTEMBER 202) LIFE SCIENCES P1 11 3.4.4 - The zygote divides by mitosis  - To form a (solid) ball of cells  - called morula  - which further divides to form a hollow ball of cells  - called blastocyst / blastula - The blastocyst/blastula implants in the endometrium  / This is called implantation - The outer layer of the embryo becomes a chorion  and - inner layer becomes an amnion  - with the amniotic fluid inside  - After the implantation the chorion develops many finger-like outgrowths  - called chorionic villi  - The endometrium together with the chorionic villi forms the placenta  (Any 8 x 1) (8) 3.4.5 - Hollow cavity  to accommodate the developing foetus  - Muscular  to contract and relax to facilitate childbirth  - Elastic  to stretch to accommodate the developing foetus  (Any 2 x 1) (2) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over