# Life Sciences Grade 12 Paper 1 Free State Mock 2022 Memo > Grade 12 Life Sciences Paper 1 memorandum from the Free State Mock Exam 2022, 30 pages. Read online or download the free PDF. - Page: https://www.hlayiso.com/library/fs-life-sciences-sept-2022-p1-and-memo/1170e9cb-d3a5-441a-a002-90bf965aa5c5 - Updated: 2026-09-27 - Subject: Life Sciences - Grade: Grade 12 - Document type: Memorandum - Year: 2022 - Exam period: Free State Mock Exam - Paper: 1 - Curriculum: CAPS - Pages: 30 Breadcrumbs: [Home](https://www.hlayiso.com/) › [Library](https://www.hlayiso.com/library) › [Grade 12](https://www.hlayiso.com/library/grade-12) › [Life Sciences](https://www.hlayiso.com/library/grade-12/life-sciences) › [Life Sciences Grade 12 Paper 1 Free State Mock 2022 Memo](https://www.hlayiso.com/library/fs-life-sciences-sept-2022-p1-and-memo/1170e9cb-d3a5-441a-a002-90bf965aa5c5) ## About this document Life Sciences · Grade 12 · Free State Mock Exam · 2022. Memorandum, 30 pages. Read online or download the PDF. Read it free online on the page above; download the PDF from there. ## Document text Text extracted from the PDF. Layout, diagrams and tables may not survive extraction. ### Page 1 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com PREPARATORY EXAMINATION GRADE 12 LIFE SCIENCES P1 SEPTEMBER 2022 MARKS: 150 TIME: 2½ HOURS This question paper consists of 20 pages. Copyright reserved Please turn over ### Page 2 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 2 com FS/September 2022 Grade 12 Prep. Exam. INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. 2. Write ALL the answers in the ANSWER BOOK. 3. Start the answers to EACH question at the top of a NEW page. 4. Number the answers correctly according to the numbering system used in this question paper. 5. s.co Present your answers according to the instructions of each question. 6. m Make ALL drawings in pencil and label them in blue or black ink. si c 7. Draw diagrams, tables or flow charts only when asked to do so. st 8. an The diagrams in this question paper are NOT necessarily drawn to scale. 9. Do NOT use graph paper. mor 10. ep You must use a non-programmable calculator, protractor and a compass, where necessary. hy 11. Write neatly and legibly. om fr oa de d do wn l Copyright reserved Please turn over ### Page 3 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 3 com FS/September 2022 Grade 12 Prep. Exam. SECTION A QUESTION 1 1.1 Various options are given as possible answers to the following questions. Choose the answer and write only the letter (A to D) next to the question numbers (1.1.1 to 1.1.10) in the ANSWER BOOK, for example 1.1.11 D. 1.1.1 Which part of the brain controls the heart rate? A Hypothalamus B Cerebrum C D Cerebellum Medulla oblongata s.co 1.1.2 m Which ONE of the following hormones prepares the body for an emergency? si c A ADH st B C Testosterone Adrenalin an D TSH mor 1.1.3 ep Which ONE of the following refers to the process whereby sperm hy and ova are produced in the testes and ovaries? A Gametogenesis B Oogenesis om C Spermatogenesis D fr Ovulation 1.1.4 oa The central nervous system is made up of the … de A B d cranial and spinal nerves. autonomic and peripheral nervous systems. do C cranial nerves and the brain. wn D brain and the spinal cord. l Copyright reserved Please turn over ### Page 4 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 4 com FS/September 2022 Grade 12 Prep. Exam. QUESTIONS 1.1.5 AND 1.1.6 ARE BASED ON THE DIAGRAM OF THE HUMAN MALE REPRODUCTIVE SYSTEM 1 2 3 4 1.1.5 Which numbered part is responsible to keep the temperature a few degrees lower than body temperature? A 1 B 2 C 3 D 4 1.1.6 Which numbered part(s) contribute(s) to the development of mature and motile sperm? A 1 B 1, 2 and 3 C 4 D 1, 2, 3 and 4 Copyright reserved Please turn over ### Page 5 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 5 com FS/September 2022 Grade 12 Prep. Exam. 1.1.7 During an investigation a man was placed in an airtight room. Sensors were used to monitor his breathing and heart rate. The investigators were able to change the environmental conditions in the room. After 30 minutes the man's breathing and heart rate increased. The investigators changed the environmental conditions in the room by … A decreasing the humidity. B decreasing the light intensity. C increasing the amount of carbon dioxide in the air. D increasing the amount of oxygen in the air. 1.1.8 The diagram represents the parts of the eye responsible for accommodation. Front view Side view lens The following statements are used to describe accommodation in the eye: (i) Ciliary muscles contract (ii) Suspensory ligaments become taut (iii) Tension on the lens increases (iv) Lens becomes more convex (v) Refractive power of the lens increases Which of the statements relate to this diagram? A (i), (ii), (iv) and (v) only B (i), (ii), (iii), (iv) and (v) C (i), (iv) and (v) only D (ii) and (iii) only Copyright reserved Please turn over ### Page 6 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 6 com FS/September 2022 Grade 12 Prep. Exam. 1.1.9 Which ONE of the following hormones controls metabolic rate? A Testosterone B Glucagon C Thyroxin D Oestrogen 1.1.10 When there is a decrease in the human body temperature, which ONE of the following shows the correct response by blood capillaries in the skin? Decrease in body temperature Dilation of blood capillaries Constriction of blood capillaries Increased Decreased Increased Decreased blood flow blood flow blood flow blood flow to skin to skin to skin to skin I II III IV A I B II C III D IV (10 x 2) (20) Copyright reserved Please turn over ### Page 7 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 7 com FS/September 2022 Grade 12 Prep. Exam. 1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the question numbers (1.2.1 to 1.2.9) in the ANSWER BOOK. 1.2.1 The strategy by the parents where food and protection are provided to increase survival of the offspring 1.2.2 The secretions that are produced in small quantities by the endocrine glands 1.2.3 The fluid surrounding the developing foetus in the uterus 1.2.4 The plant hormone responsible for the germination of seeds 1.2.5 A structure in the head of a sperm containing enzymes 1.2.6 The functional gap at which a nerve impulse passes from one neuron to another 1.2.7 The liquid secreted by the testes and associated glands 1.2.8 The shedding of the endometrium and an unfertilised ovum 1.2.9 The protective membrane covering the cornea of the eye (9 x 1) (9) 1.3 Indicate whether each of the descriptions in COLUMN I applies to A ONLY, B ONLY, BOTH A AND B or NONE of the items in COLUMN II. Write A only, B only, both A and B or none next to the question numbers (1.3.1 to 1.3.3) in the ANSWER BOOK. COLUMN I COLUMN II 1.3.1 Secretions are released into a A: Endocrine gland cavity/duct of the body B: Exocrine gland 1.3.2 The young develop and is A: Vivipary nourished in an amniotic egg B: Ovipary that is retained in the mother's body 1.3.3 Increases the permeability of A: Less ADH the renal tubes for B: More ADH osmoregulation (3 x 2) (6) Copyright reserved Please turn over ### Page 8 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 8 com FS/September 2022 Grade 12 Prep. Exam. 1.4 The diagram below shows the female reproductive system. A E B C D 1.4.1 Identify part: (a) A (1) (b) C (1) 1.4.2 Give the LETTER only of the part, where each of the following takes place: (a) Meiosis (1) (b) Fertilisation (1) 1.4.3 State TWO functions of part E. (2) 1.4.4 Name the glands which secrete nutrient rich fluid for the sperm, to reach part A. (1) (7) Copyright reserved Please turn over ### Page 9 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 9 com FS/September 2022 Grade 12 Prep. Exam. 1.5 The diagrams below represent different disorders or defects in the human body. Diagram A Diagram B Normal thyroid Enlarged thyroid gland Diagram C Diagram D More than one focus point Cochlear implant 1.5.1 Identify the following represented in Diagram B: (a) The disorder (1) (b) Possible dietary cause of the disorder (1) 1.5.2 Name the visual defect represented in diagram: (a) A (1) (b) D (1) 1.5.3 Give a possible cause of the image falling on more than one focus point in Diagram D. (1) Copyright reserved Please turn over ### Page 10 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 10 com FS/September 2022 Grade 12 Prep. Exam. 1.5.4 Name the defect that is treated with a cochlear implant as (1) shown in Diagram C. 1.5.5 Name the defect: (a) Where the lens becomes cloudy (opaque) and prevents light from reaching the retina. (1) (b) Treated with the insertion of a grommet in the tympanic membrane. (1) (8) TOTAL SECTION A: 50 Copyright reserved Please turn over ### Page 11 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 11 com FS/September 2022 Grade 12 Prep. Exam. SECTION B QUESTION 2 2.1 The diagram below represents two human gametes. Gamete I Gamete II C B A D 2.1.1 What is the function of layer C? (1) 2.1.2 Explain the role that part B plays in increasing the chances of fertilisation. (2) 2.1.3 Describe the significance of the chromosome number of part A. (2) 2.1.4 Use a flow diagram to give the correct sequence of the developmental stages of a fertilised ovum until a foetus is formed. (2) (7) Copyright reserved Please turn over ### Page 12 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 12 com FS/September 2022 Grade 12 Prep. Exam. 2.2 The female foam-nest tree frog releases a batch of eggs which are then fertilised by sperm from her mating partner as well as other nearby males. As the eggs are laid male frogs will cover it with foam. These foam nests are found in water puddles, tree branches, or buried underground. The nests prevent dehydration (drying out), predation and infection from bacteria and fungi. It also provides a healthy environment for the developing embryos. Sunlight will harden the nest's outer surface. After a few days the developing tadpoles break out and fall into the water where they will complete their development. [Adapted from: https://www.sciencedirect.com/science/article] 2.2.1 State the type of fertilisation used by the foam-nest tree frogs. (1) 2.2.2 State TWO ways in which the chances of fertilisation in these frogs are increased. (2) 2.2.3 Give TWO functions of the foam nests. (2) (5) Copyright reserved Please turn over ### Page 13 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 13 com FS/September 2022 Grade 12 Prep. Exam. 2.3 The diagram below represents a reflex arc. Neuron B Neuron A Neuron C 2.3.1 What is a reflex arc? (2) 2.3.2 Explain the effect on the reflex action when neuron C is damaged. (2) 2.3.3 Name the disorder that is the result in the break down of the myelin sheath of neurons. (1) (5) 2.4 The autonomic nervous system controls all involuntary actions in the human body and conducts impulses from the central nervous system. 2.4.1 Name TWO locations that impulses from the autonomic nervous system are conducted to. (2) 2.4.2 Describe the functioning of the autonomic nervous system. (5) (7) Copyright reserved Please turn over ### Page 14 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 14 com FS/September 2022 Grade 12 Prep. Exam. 2.5 The graph below shows the hormonal changes in a female's body during pregnancy. Hormone levels during pregnancy Hormone levels in blood (arbitrary units) oestrogen progesteronefrom progesterone from structure structure B B progesterone progesterone from structure A from structure A prolactin Time (weeks) 2.5.1 Identify the following structures: (a) A (1) (b) B (1) 2.5.2 Name the gland where prolactin is produced. (1) 2.5.3 Explain the high secretion of prolactin after week 40. (2) 2.5.4 Explain the significance of the levels of oestrogen and progesterone dropping towards the end of pregnancy. (2) 2.5.5 Describe the effect that the drop in progesterone level has on the ovarian cycle. (5) (12) Copyright reserved Please turn over ### Page 15 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 15 com FS/September 2022 Grade 12 Prep. Exam. 2.6 The diagram below represents part of the inner ear. B A C 2.6.1 Identify part: (a) B (1) (b) C (1) 2.6.2 Describe the role of the structures of the ear from the time that a sound wave reaches the ear until pressure waves are set up in the inner ear. (7) 2.6.3 Name part A and explain the consequences if it gets damaged. (5) (14) [50] Copyright reserved Please turn over ### Page 16 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 16 com FS/September 2022 Grade 12 Prep. Exam. QUESTION 3 3.1 The diagram below represents the homeostasis of blood glucose in the human body. Hormone X Liver Low blood sugar Alpha cells C Endocrine tissue Responses in organ Z High Beta cells blood sugar Blood vessel Hormone Y 3.1.1 Identify hormone Y. (1) 3.1.2 Name: (a) Organ Z (1) (b) The endocrine tissue in organ Z. (1) 3.1.3 Describe the response that is carried out when a person has not eaten any sugar-containing food for six hours. (6) (9) Copyright reserved Please turn over ### Page 17 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 17 com FS/September 2022 Grade 12 Prep. Exam. 3.2 The following diagram represents a human foetus at 36 weeks of gestation. X 3.2.1 Identify part X. (1) 3.2.2 Name and describe the functions of the different blood vessels found in part X. (4) (5) Copyright reserved Please turn over ### Page 18 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 18 com FS/September 2022 Grade 12 Prep. Exam. 3.3 An experiment was set up to investigate the diameter of the pupil under different light conditions. A person sat in a dark room and an electric light bulb was switched on at different distances from the person. The diameter of the pupil was measured 1 minute after each time the light bulb was switched on. The results are illustrated in the graph below. Diameter of the pupil in relation to the position of a light source 9 8 Diameter of the pupil (mm) 7 6 5 4 3 2 1 0 1 2 3 4 5 6 Position of the light source 3.3.1 Name the following for this investigation: (a) Independent variable (1) (b) Dependent variable (1) 3.3.2 State TWO reasons why the results of this investigation are not reliable. (2) 3.3.3 Calculate the percentage decrease in the pupil diameter, when the light bulb was moved from position 3 to position 4. Show all your calculations. (3) 3.3.4 Which coloured structure in the eye is responsible for changing the diameter of the pupil? (1) 3.3.5 Name the mechanism that caused the change in the diameter of the pupil from position 2 to position 3. (1) 3.3.6 Describe the mechanism mentioned in QUESTION 3.3.5. (3) Copyright reserved Please turn over ### Page 19 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 19 com FS/September 2022 Grade 12 Prep. Exam. 3.3.7 Give the: (a) Diameter of the pupil at position 4 of the light source. (1) (b) Position where the light source was the furthest form the person (1) (14) 3.4 The diagram below represents the human endocrine system. A B C D E 3.4.1 Write down the LETTER and the NAME of the gland that produces a hormone that controls the growth of long bones. (2) 3.4.2 Gland E is only found in males. Explain the consequence if gland E cannot secrete its hormone. (2) 3.4.3 Describe the homeostatic control if the salt levels in the blood are low. (4) 3.4.4 Name TWO other substances or factors, except salt, that should be kept constant in the internal environment of the tissue fluids. (2) (10) Copyright reserved Please turn over ### Page 20 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 20 com FS/September 2022 Grade 12 Prep. Exam. 3.5 Phototropism was investigated in young stems. A group of stem tips were exposed to a unilateral light. The stem tips were treated differently. Stem A's tip was intact, stem B's tip was removed, and stem C's tip was covered with a black cap. In diagram D the tip was removed, and agar (jelly-like substance) was placed between the tip and the stem. The diagrams below show the different treatments and results. The arrows indicate the position of a unilateral light source. A B C D agar Stem Tip Tip covered Tip removed and intact removed with black a piece of agar is placed cap on top. The tip of the stem is placed back on top of the agar 3.5.1 Name the plant hormone that causes the growth movements illustrated in the diagrams? (1) 3.5.2 Define phototropism. (2) 3.5.3 Explain why stem D grows towards the light source. (6) 3.5.4 Explain the result of the experiment with stem C. (3) (12) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over ### Page 21 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 1 com FS/September 2022 Grade 12 Prep. Exam. Marking Guidelines PREPARATORY EXAMINATION GRADE 12 LIFE SCIENCES P1 SEPTEMBER 2022 MARKS: 150 MARKING GUIDELINES These marking guidelines consist of 10 pages. Copyright reserved Please turn over ### Page 22 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 2 com FS/September 2022 Grade 12 Prep. Exam. Marking Guidelines 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. Copyright reserved Please turn over ### Page 23 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 3 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 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. 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. 19. Changes to the memorandum No changes must be made to the memoranda. The provincial internal moderator must be consulted. Copyright reserved Please turn over ### Page 24 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 4 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline SECTION A QUESTION 1 1.1 1.1.1 D  1.1.2 C  1.1.3 A  1.1.4 D  1.1.5 D  1.1.6 B  1.1.7 C  1.1.8 C  1.1.9 C  1.1.10 D  (10 x 2) (20) 1.2 1.2.1 Parental care  1.2.2 Hormones  1.2.3 Amniotic  fluid 1.2.4 Gibberellin  1.2.5 Acrosome 1.2.6 Synapse /synaptic cleft 1.2.7 Semen  1.2.8 Menstruation  1.2.9 Conjunctiva  (9 x 1) (9) 1.3 1.3.1 B only  1.3.2 None  1.3.3 B only  (3 x 2) (6) 1.4 1.4.1 (a) Fallopian tube  (1) (b) Cervix  (1) 1.4.2 (a) B  (1) (b) A  (1) 1.4.3 - Responsible for the protection of the embryo  from implantation to birth - provides space for the developing foetus  (2) 1.4.4 Seminal vesicles  (1) (7) Copyright reserved Please turn over ### Page 25 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 5 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 1.5. 1.5.1 (a) Goitre  (1) (b) A lack of iodine  in the diet (1) 1.5.2 (a) Short-sightedness /Myopia (1) (b) Astigmatism  (1) 1.5.3 (The reflection of light from) an irregularly shaped cornea  (1) 1.5.4 Deafness /hearing loss/hearing impairment (1) 1.5.5 (a) Cataracts ✓ (1) (b) Middle ear infection ✓ (1) (8) TOTAL SECTION A: 50 SECTION B QUESTION 2 2.1 2.1.1 - The jelly layer provides protection  for the early developmental stages of the fertilised egg - Facilitates the movement of the ovum/embryo through the fallopian tube  (Any) (1) 2.1.2 It provides the sperm with energy  for locomotion.  (2) 2.1.3 Part A is haploid /has 23 chromosomes to ensure that after fertilisation the zygote has a diploid  number of chromosomes/46 chromosomes. (2) 2.1.4 zygote morula blastula/blastocyst  foetus (2) (7) 2.2 2.2.1 External  fertilisation (1) 2.2.2 - The frogs are close to each other  - Many males mate with a female  - Many gametes  (ova and sperm) are released (Any) (2) (Mark first TWO only) Copyright reserved Please turn over ### Page 26 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 6 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 2.2.3 - Prevent dehydration  of the developing tadpoles/embryos - Protect the developing tadpoles/embryos from predation  - Prevent microbial degradation  and - Provide a healthy environment  for the embryos (Mark first TWO only) (Any) (2) (5) 2.3 2.3.1 The pathway along which nerve impulses are carried from a receptor to an effector to bring about a reflex action.  (2) 2.3.2 A person would be able to feel the sensation  but is unable to react  to the stimuli. (2) 2.3.3 Multiple sclerosis  (1) 2.4 2.4.1 Smooth muscles  Heart muscle Glands  (Any) (2) (Mark first TWO only) 2.4.2 - Every organ/gland are controlled by two sets of nerves  - that act antagonistically  Autonomic nervous system is divided into - Sympathetic nerves  and - Parasympathetic nerves  - Sympathetic nerves stimulate  - fight of flight function  in emergency situations - Parasympathetic inhibits  a response and - restores the body to normal  (Any) (5) (12) 2.5 2.5.1 (a) Corpus luteum  (1) (b) Placenta  (1) 2.5.2 Pituitary gland /Hypophysis (1) 2.5.3 - The foetus was born  after 40 weeks, and - milk is the only food source  for the baby/milk must be produced/After birth, prolactin stimulates milk production/lactation to feed the baby (2) 2.5.4 There is no need to maintain the endometrium any longer  and allows the placenta's removal/release  (2) Copyright reserved Please turn over ### Page 27 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 7 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 2.5.5 - The drop in progesterone level - stimulates the pituitary gland /hypophysis - to secrete FSH  - The high level of FSH stimulates the development of a primary follicle  - into a graafian follicle  that - leads to ovulation  (5) (12) 2.6 2.6.1 (a) Semi-circular canals  (1) (b) Cochlea  (1) 2.6.2 - The pinna directs sound waves  - into the auditory canal  - The auditory canal transmits sound waves to the tympanic membrane  - The tympanic membrane transmits sound waves to the middle ear /ossicles as vibrations - The ossicles transmit  - and amplify  the vibrations - to the oval window  - which vibrates and transmits the vibrations to the inner ear (Any) (7) 2.6.3 - The auditory nerve * - No impulses can be transmitted to the cerebrum  and - cerebellum  - which leads to a loss of hearing  and - a loss of balance  (*Compulsory mark + 4) (5) (14) [50] Copyright reserved Please turn over ### Page 28 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 8 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline QUESTION 3 3.1 3.1.1 Insulin  (1) 3.1.2 (a) Pancreas  (1) (b) Islets of Langerhans  (1) 3.1.3 - Negative feedback reaction  - The glucose concentration in the blood drops below normal  - The alpha cells/islets of Langerhans/pancreas detect the drop and secretes glucagon  - in the blood  - which is transported to the liver /muscle cells - Glucagon stimulates the conversion of glycogen to glucose  - The glucose concentration in the blood returns to - normal  (Any) (6) (9) 3.2 3.2.1 Umbilical cord  (1) 3.2.2 - The umbilical arteries  * - carry deoxygenated blood /waste products - to the placenta  - and an umbilical vein * - carries oxygenated blood /nutrients - from the placenta to the foetus (2 *Compulsory marks + 2 x 1) (4) (5) 3.3 3.3.1 (a) Different light conditions  (1) (b) Diameter of the pupil  (1) 3.3.2 Only one person  participated in the experiment/small sample size The experiment was not repeated /only done once (2) 3.3.3 8–5  100 8 x 1  = 37,5 % (3) 3.3.4 Iris  (1) 3.3.5 Pupil mechanism  (1) Copyright reserved Please turn over ### Page 29 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 9 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 3.3.6 Circular muscles of the iris relax  Radial muscles of the iris contract  Pupil diameter increases  (3) 3.3.7 (a) 5 mm (1) (b) 3  (1) (14) 3.4 3.4.1 A - Pituitary gland /Hypophysis (2) 3.4.2 - No development of secondary male features /Any example - No sperm will develop ✓/sperm count will be low (2) 3.4.3 - The adrenal glands are stimulated  - to secrete more aldosterone  - More sodium ions are reabsorbed  - from the distal convoluted tubules /collecting ducts - into the surrounding blood capillaries  - Salt levels in the blood return to normal  (Any) (4) 3.4.4 Water  pH  carbon dioxide  glucose  temperature  (Any) (2) (Mark first TWO only) (10) 3.5 3.5.1 Auxins  (1) 3.5.2 The growth movement of part of a plant in response to a unilateral light stimulus.  (2) 3.5.3 - Auxins diffuse through the agar to the stem  - Auxins are light sensitive /are destroyed by light/Auxins move away from light  - There is a higher concentration of auxins on the dark side of the stem  - Growth is stimulated  on the dark side which - grows faster  - causing the stem to grow/bend towards the light  (Any) (6) Copyright reserved Please turn over ### Page 30 Downloaded from hlayiso.com Downloaded f rom St anmorephysics. Life Sciences P1 10 com FS/September 2022 Grade 12 Prep. Exam. Marking Guideline 3.5.4 - Light will not reach the tip of the stem  - Therefore, auxins are distributed evenly  throughout the tip of the stem - The stem will grow straight up /no bending towards the light (3) (12) [50] TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over ## Related documents - [Life Sciences P1 May June 2022 Eng](https://www.hlayiso.com/library/life-sciences-p1-may-june-2022-eng/88be2a14-1b51-47ea-bec4-810a3bbfd3b4) — Life Sciences · QP · 2022 · Eng - [Life Sciences P1 Nov 2022 Eng](https://www.hlayiso.com/library/life-sciences-p1-nov-2022-eng/c0ba0c20-6c29-4abe-aef0-baeb48113dd3) — Life Sciences · QP · 2022 · Eng - [LIFE SCIENCES P2 GR12 MEMO SEPT2022 Afrikaans](https://www.hlayiso.com/library/life-sciences-p2-gr12-memo-sept2022-afrikaans/7cca7322-63ed-4fb0-a67b-5df57d647597) — Life Sciences · Memo · 2022 · Afr - [Gr12 Life Sciences P2 (English) SEP 2022 Possible Answers](https://www.hlayiso.com/library/gr12-life-sciences-p2-english-sep-2022-possible-answers/17f73f27-a44f-41f5-b5d9-656090338f3e) — Life Sciences · Memo · 2022 · Eng - [Limpopo Life Sciences Grade 12 SEPT 2022 P2 and Memo](https://www.hlayiso.com/library/limpopo-life-sciences-grade-12-sept-2022-p2-and-memo/a14d1ac1-f20f-44b6-9531-44480fcf1d4c) — Life Sciences · Memo · 2022 - [LIFE SCIENCES P1 MEMO GR12 SEPT2024 English](https://www.hlayiso.com/library/life-sciences-p1-memo-gr12-sept2024-english/fa4befb2-edb6-4abd-ab23-dadee10f33fc) — Life Sciences · Memo · 2024 · Eng ## More from Grade 12 Life Sciences - [LIFE SCIENCES QP GR12 JUNE 2025 ENG D watermark](https://www.hlayiso.com/library/life-sciences-qp-gr12-june-2025-eng-d-watermark/138939cb-4757-4989-99d7-c9cb21429a5c) — QP · 2025 · Eng - [Life Sciences Grade 12 NSC QP March 2025 KZN](https://www.hlayiso.com/library/life-sciences-grade-12-nsc-qp-march-2025-kzn/b1598f8e-58e0-4c09-b513-b9f61ae73c47) — QP · 2025 - [Life Sciences Grade 12 NSC P2 MEMO September 2025 Mpumalanga](https://www.hlayiso.com/library/life-sciences-grade-12-nsc-p2-memo-september-2025-mpumalanga/17b4cc42-641c-4d7d-9c53-6bac113ce83c) — Memo · 2025 - [Life Sciences Grade 12 NSC P1 QP September 2025 Mpumalanga](https://www.hlayiso.com/library/life-sciences-grade-12-nsc-p1-qp-september-2025-mpumalanga/be917127-6071-4190-b900-3c475d5bfdd4) — QP · 2025 - [Life Sciences Grade 12 NSC P1 QP September 2025 North West](https://www.hlayiso.com/library/life-sciences-grade-12-nsc-p1-qp-september-2025-north-west/9dc29799-a675-40eb-9573-df7341b3572f) — QP · 2025 - [Life Sciences P2 May-June 2025 Afr](https://www.hlayiso.com/library/life-sciences-p2-may-june-2025-afr/f068fe02-7f70-4bf4-91ad-4ead880d1a88) — QP · 2025 · Afr ## Collection - [Grade 12 past papers](https://www.hlayiso.com/grade-12/past-papers) --- Hlayiso: free CAPS and IEB past papers, memos, notes and study guides for South African learners. 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