Life Sciences Grade 12 Paper 1 Limpopo Prelim 2024 Memo

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com T,TL RA POS PO PROVINCIAL GOVERNMENT REPUBLIC OF SOUTH AFRICA DEPARTMENT OF EDUCATION NATIONAL SENIOR CERTIFICATE [ GRADE 12 MARKS: 150 DURATION: 2%2 HOURS This question paper consists of 13 pages

Downloaded from hlayiso.com Life ScicReeyeahonmtech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. Answer ALL the questions. Write ALL the answers in the ANSWER BOOK. Start the answers to each question at the top of a NEW page. PON Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Do ALL drawings in pencil and label them in blue or black ink. Draw diagrams, flow charts or tables only when asked to do so. PN oo The diagrams in this question paper are NOT necessarily drawn to scale. 9. Do NOT use graph paper. 10. You may use a non-programmable calculator, protractor and compass, where necessary. 11.Write neatly and legibly. Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScieReeveatonitech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 NSC SECTION A 1.1 QUESTION 1 Various options are provided 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 1.1.9) in the ANSWER BOOK, e.g. 1.1.10D. Which ONE of the following occurs when an apical bud from a rose bush is regularly removed? The rose bush will... . regulate appeti le. B. inhibit voluntary movements. C. control higher thought processes. D. control muscle tone and balance. Which of the following parts of the brain co-ordinates voluntary movements? A. Cerebellum B. Spinal cord C. Cell body D. Meninges The tough, non-elastic tissue that covers the outer part of the eyeball is the... A. sclera. B. conjunctiva. C. choroid. D. retina. The amniotic fluid that surrounds the developing embryo of a human helps to... A. transport oxygen to the developing embryo. B. transport carbon dioxide to the developing embryo. C. protect the embryo against mechanical injury. D. transport nitrogenous waste substances to the developing embryo. Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScicReeyeahonmtech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 QUESTIONS 1.1.6 AND 1.1.7 REFER TO THE INVESTIGATION BELOW. Ascientist did an investigation to determine the effect of drinking water on urine production. A healthy athlete was requested not to drink water or eat food for five hours before the investigation started. The investigation was conducted over a period of three days. The following procedure was followed. - Day 1, the athlete was given 500ml of water to drink. - Day 2, the athlete was given 700m! of water to drink. - Day 3, the athlete was given 900ml of water to drink. - Oneach day of the investigation, the amount of urine produced by the athlete was measured and recorded over a four hour period after drinking the water. - The average was calculated. 1.1.6 Which ONE of the following CORRECTLY indicates the dependent and independent variable? Independent variable Dependent variable A The amount of urine produ Time in hours B The amount of The amount of urine consumed produced Cc The amount The amount of water consumed D The person pa ting Time in hours 1.1.7 The list below PA, s before and after the investigation. (i) Permission was obtained from the athlete. (ii) The measuring tool was decided upon. (iii) | The amount of water was measured. (iv) | The duration of the investigation was decided upon. Which of the planning steps above are correct? A. (i), (ii) and (iii) B. (i), (iii) and (iv) C. (ii), (iii) and (iv) D. (i), (ii) and (iv) 121-8 Which ONE of the following is a function of gibberellins? A. Slows down the germination of seeds. B. Stimulate the germination of seeds. C. Promotes the ageing of leaves. D. Brings about tropism. Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScicReyeattiondeeh frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 149 Which ONE of the following is a characteristic of external fertilisation? A. The embryo is protected inside the body of the female. B. Copulation takes place. C. Alarge number of ova are produced. D. Sperm is introduced into the body of the female. (9x2) (18) 12 Give the correct biological term for each of the following descriptions. Write only the term next to the question numbers (1.2.1.to 1.2.10) in the ANSWER BOOK. 12.1 A process where an embryo attaches itself into the endometrium. 122 The division of the nervous system that is made up of the cranial and spinal nerves. 172.3 A hormone that stimulates the mammary s to luce milk. 1.2.4 The outer membrane that encloses i us of a human. i 5 1:2.5. The structure that connects the left and tighthemi SI of the cerebrum. : 12:6 The blood vessel in the umbilical cord that transports nutrients to the foetus. 12-7 A disorder of the nervous system caused by the breakdown of the myelin sheath of neurons. 128 The open passage through which sound waves travel to the middle ear. 12.9 The external physical structures used by plants that prevents herbivores from feeding on them. 1.2.10 A behavioural pattern of animals feeding their young and protecting them from predators. (10x 1) (10) Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScieReeypeatonttect frenvSitanmorephysics.com LIMPOPO DoE/ Sep 2024 1.3 Indicate whether each of the descriptions in COLUMN | apply 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 number (1.3.1 to 1.3.3) in the ANSWER BOOK. COLUMN | COLUMN II 1.3.1. A hormone that stimulates the secretion | A: Testosterone of the hormone of the thyroid gland B: Abscisic acid 1.3.2.-A part of the ear that absorbs sound A: Round window waves from the inner ear B: Pinna 1.3.3. A gland that has ducts to transport its A: Endocrine gland secretions to where they are needed B: Exocrine gland (3x2) (6) 1.4 The diagram below represents a part of the human central nervous system. 1.4.1. Identify part: (a)A (1) (b)D (1) (c) Microscopic gap at E (1) 1.4.2 Give the LETTER and NAME of the part which is probably damaged if a person... (a) can walk, but cannot detect any stimulus. (2) (b) can feel the stimulus, but cannot respond. (2) Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScicReeyeahonmtech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 1.4.3 Write down in the correct order the LETTERS ONLY of the path taken by a nerve impulse until a response takes place. (2) 1.4.4 Give the name of the process which enables a person to quickly and involuntarily respond to a stimulus. (1) (10) 1:5. The diagram below represents the human endocrine system. 1.5.1 Identify gland: (a) C (1) (b) D (1) 1.5.2 Give the name of the hormone that... (a) Is involved in the reabsorption of salts in the renal tubules of the (1) kidneys. (b) Controls the growth of long bones. (1) 1.5.3 Name the disease that results when gland C is unable to produce the hormone insulin. (1) 1.5.4 Name the type of interaction that occurs between the hormones secreted by glands A and B. (1) (6) TOTAL QUESTION 1: 50 TOTAL SECTION A: [50] Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScieReeveatonitech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 NSC SECTION B QUESTION 2 24 The diagram below represents the human ear. 2.1.1 Identify part: (a)c (1) (b)D (1) (c)E (1) 2.1.2 State ONE function of part F. (1) 2.1.3. Middle ear infection is a common cause for loss of hearing. Name ONE way in which middle ear infection can be treated. (1) 2.1.4 Describe how part A, B and E assists in amplifying sound. (4) 2.1.5 Describe how the semi-circular canals play a role in maintaining balance when the body changes speed and direction. (5) (14) Copyright reserved Please turn over

Life Sciceveevemutegh frenSitanmorephysics. com 2.2 22:1 2.2.2 2.2.3 2.3 2.4 2.4.1 2.4.2 2.4.3 Copyright reserved Downloaded from hlayiso.com The diagram below represents the female reproductive system. Give the LETTER and NAME of the part where: (a) Fertilisation takes place. (b) The embryo develops. State TWO functions of part D. Name and describe the type of gametogenesis that takes place in part A. Draw a labelled diagram to show the structure of a haploid cell that will fuse with a haploid cell produced in part A. The table below indicates the growth of a human foetus six months after fertilisation has taken place. Months after fertilisation 1 4 3 4 5 6 Length of foetus (cm) 0,5 4 iS 15 25 30 Between which two consecutive months did foetal growth double? What is the percentage increase in foetus length between the 3 and 6" month after fertilization? Show ALL working. Draw a line graph to represent the data in the table. LIMPOPO DoE/ Sep 2024 (2) (2) (2) (5) (11) (5) (1) (3) (6) (10) Please turn over

Downloaded from hlayiso.com Life ScicReyeattiondeeh frenSitanmorephysics.com LIMPOPO DoE/ Sep 2024 2.5 The graph below represents a menstrual cycle and the influence of the different hormones on it. @ Ovula si anal | Progesterone Pituitary hormone levels Ovarian events \ Ovarian hormone levels ‘G Uterine events 9 Ss 2.5.1 On which day does ovulation take place? (1) 2.5.2 Between which days does menstruation take place? (1) 2.5.3 State ONE function of LH other than ovulation. (1) 2.5.4 Describe the functional relationship between progesterone and FSH. (2) 2.5.5 Account for the change in the thickness of the endometrial lining between day 14 and day 21. (2) 2.5.6 Did fertilisation take place in the 28-day cycle illustrated in the graph? (1) 2.5.7 Explain your ANSWER to question 2.5.6. cn TOTAL QUESTION 2: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScieReeypeatonttect frenvStanmorephysics.com LIMPOPO DoE/ Sep 2024 The table below shows a comparison of the composition of the amniotic egg in different bird species. COMPOSITION BIRD SPECIES 1 2 3 Yolk (%) 30 38 18 Water content in yolk (%) 79 59 57 Energy (kcal/g) 1,16 1,46 1,03 Define ovovivipary (2) Which ONE of the bird species (1, 2 or 3) shows altricial development as a reproductive strategy? (1) Explain your answer to QUESTION 3.1.2. (2) (5) QUESTION 3 3.1 3.1.1 3.1.2 3.1.3 3.2 Dale did an investigation to determine the effect of auxins on the growth of three plant shoots (A, B and C). The plant shoots were treated as follows: e Shoot A — Tip of the shoot was not removed e Shoot B — Tip removed and an agar plate with auxins placed on top e Shoot C-— Tip removed and agar plate without auxins placed on top (Agar is a jelly-like substance that allows auxins to diffuse through it) All shoots were exposed to the same light conditions. The diagram below indicates the set-up at the beginning of the investigation. Agar plate Agar plate with auxins without auxins Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScicReeyeahonmtech frenSitanmorephysics. com LIMPOPO DoE/ Sep 2024 3.2.1 Explain the results as observed in: (a) Shoot B after a few days (2) (b) Shoot C after a few days (2) 3.2.2 State TWO factors that must be kept constant in this investigation. (2) 3.2.3 State TWO ways in which Dale could have improved the reliability of her investigation. (2) (8) 3.3 The diagrams below show parts of the human eye Diagram 1 Diagram 2 3.3.1. Give the LETTER and NAME of the part that regulates the amount of light that enters the eye. (2) 3.3.2 Name and describe the process that the part named in QUESTION 3.3.1 will undergo when exposed to bright light. (5) 3.3.3 Explain how part A is structurally suited to perform its function. (2) 3.3.4 State TWO functions of the liquid in part E. (2) 3.3.5. Which diagram (1 or 2) is adapted to distant vision? (1) 3.3.6 Give a reason for your answer to question 3.3.5. (1) 3.3.7 Describe how the changes in the lens from diagram 1 to diagram 2 are brought about. (5) (18) Copyright reserved Please turn over

Downloaded from hlayiso.com Life ScicReyeattiondeeh frenvSitanmorephysics.com LIMPOPO DoE/ Sep 2024 3.4 The diagram below represents a homeostatic response that occurs when a person is dehydrated. The decrease in blood volume, as a result of the excessive loss of water, is detected by the brain 3.4.1. Define the term homeostasis. (2) 3.4.2 Identify: (a) Hormone X. (1) (b) Target organ Y. (1) (4) 3.5 Describe what happens when the Carbon dioxide level in the blood increases above normal. (5) 3.6 Read the passage below Sphiwe was walking alone in the bush. She suddenly saw a big snake and she was very frightened. She screamed asking for help, turned around and ran away. During that time, she was breathing heavily and her eyes were wide open. 3.6.1 Name the hormone that prepared the body to evade the danger. (1) 3.6.2 State the role of the liver during an emergency. (1) 3.6.3 Explain the effects of the hormone mentioned in question 3.6.1 on the blood vessels of skeletal muscles. (4) (6) 3.7 Explain how the thyroid gland is functionally related to body temperature on a cold day. (4) TOTAL QUESTION 3: 50 TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com LIMPOPO PROVINCIAL GOVERNMENT REPUBLIC OF SOUTH AFRICA DEPARTMENT OF EDUCATION NATIONAL SENIOR CERTIFICATE MARKS: 150 This MARKING GUIDELINES consists of 10 pages Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com 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 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. te 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 becomes correct again, resume credit. 9. Non-recognized abbreviations Accept if first defined in answer. If not defined, do not credit the unrecognised abbreviation but credit the rest of 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 recognizable, accept, provided it does not mean something else in Life Sciences or if it is out of context. 13: If common names given in terminology Accept, provided it was accepted at the National memo discussion meeting. 14. If only letter is asked for and only name is given (and vice versa) No credit. Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorepbysics.com 15. 16. f= 18. If units are not given in measurements Memorandum will allocate marks for units separately, except where it is already given in the question. Be sensitive to the sense of an answer, which may be stated in a different way. Caption Credit will be given for captions to all illustrations (diagrams, graphs, tables, etc.) except where it is already given in the question. Code-switching of official languages (terms and concepts) A single 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 is applicable to all official languages. Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com SECTION A QUESTION 1 1.1 (9x2) (18) 1:2 1.2.1 Implantation’ 1.2.2 PeripheralVnervous system 1.2.3. Prolactinv 1.2.4 Chorionv 1.2.5 Corpus callosumv . 1.2.6 Umbilical veinv 1.2.7. Multiple sclerosisW 1.2.8 auditory canalv 1.2.9 Thorns” 1.2.10 Parental carev (10 x1) (10) 41:3 1.3.1. Nonevv 1.3.2 Aonlyvv 1.3.3. Bonlyvv (3x2) (6) 1.4 1.4.1 (a) EffectorY/muscle (1) (b) Interneuron” /connector/relay (1) (c) SynapseY (1) 1.4.2 (a) CY — Sensory neuronY (2) (b) BY - Motor neuron’ (2) 1.4.3 C,D,B vv /CDBA (In the correct order) (2) 1.4.4 Reflex action’ (1) (10) 15 1.5.1 (a) PancreasY (1) (b) Adrenal Y gland (1) 1.5.2 (a) Aldosteronev (1) (b) Growth hormonev / GH / STH (1) 1.5.3 Diabetes Y mellitus (1) 1.5.4 Negative feedback mechanismv (1) (6) TOTAL SECTION A: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorepbysics.com SECTION B QUESTION 2 2.1 2.1.1. (a) Auditory nervev / cochlear nerve (1) (b) Cochlea¥ (1) (c) Oval window V / fenestra ovalis (1) 2.1.2 | Equalises pressure on both sides of the eardrumv tympanum / tympanic membrane (Mark FIRST ONE only) (1) 2.1.3 - use of grommetsY - antibiotics v (Mark FIRST ONE only) (1) 2.1.4 - the sound vibrations are transmitted from the large tympanic membranev /A - to the smaller oval window” - through the ossiclesvY / B - which are arranged from largest to smallestv - this concentrates the vibrationsv thus amplifying them Any (4) 21,5 ion of movement d into an impulseY d to the cerebellumy vey / vestibular nerve =) com Wa to the skeletal muscles v to restore balance (5) (14) 22 2.2.1 (a) BY — Fallopian tube / oviduct (2) (b) CY — UterusY (2) 2.2.2 -it receives the penis during copulation’ - place where semen is released during ejaculation’ - itis a birth canalv (Mark FIRST TWO only) (2) 2.2.3 -Oogenesis*v - Diploid cellsY / germinal epithelial cells - in the ovary undergo mitosis“ - to form numerous follicles” - under the influence of FSHY - one cell inside the follicle enlarges and undergoes meiosis - to form a haploid ovumv (1*Compulsory mark+ Any4) (5) (11) Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorepbysics.com 2.3 Sperm cell Middle-Piece Nucleus Acrosome Caption (C) 1 mark Correct diagram (D) 1 mark 3 correct Labels (L) 3 marks (5) 2.4 2.4.1 3and4v (Mark FIRST ONE only) (1) 2.4.2 30-7,5 v v 75 x 100 = 300%Y (3) Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com 24.3 2.5 25:41 2.5.2 2.5.3 2.5.4 2.5.5 Copyright reserved '> O .0) Length of foetus in cm after six months nn) Criteria for marking graph Criteria Mark allocation Line graph is drawn (T) 1 Caption of graph _ include both variables(C) 1 Correct labels for X and Y axis(L) 1 Correct scale for X and Y axis (S) 4 Plotting (P) 1-4 Co-ordinates plotted 1 All co-ordinates correct 2 (10) Day 14v/15 (accept 15) (1) Day 1-4~ (1) - Stimulates the formation of the corpus luteumv (1) - an increase in the level of progesterone*v - inhibits the secretion of FSHY - no follicle will developy OR - a decrease in the level progesterone*v - stimulates the secretion of FSHY - new follicle will develop” (1* Compulsory mark + Any1) (2) - the corpus luteum starts to secrete progesteronev / highest levels of progesterone - that continues to thicken the endometrium” (2) Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com 2.5.6 Nov (1) 2.5.7 - corpus luteum degeneratedv - progesterone levels decreasedvY - FSH levels start to increasev - LH levels decreaseY - endometrium breaks downY Any (2) (10) TOTAL QUESTION 2: 50 QUESTION 3 31 3.1.1. Eggs are retained/hatch inside the female body and the young are born livev v (2) 3.1.2 3v (Mark FIRST ONE only) (1) 3.1.3. - the egg has the lowest/least yolkv /energy content - this will not allow maximum development before hatchingY (2) (5) 3.2 3.2.1 (a) — shoot will grow straight upwardsY — auxins in the agar gel diffused evenly downwardsv — causing equal growth on both sides of the shootv/cell elongation — no lateral branches will developY Any (2) (b) — No upward growthy — since there is no auxinsY — lateral branches developY Any (2) 3.2.2 — same type of plantv — same age of plantw — measure length at the same timev — same environmental conditions” / (any example) — tip removed at the same timev — tip removed at the same lengthy — same concentration/ amount of auxinsv — same type of agarv Any (2) 3.2.3 — Repeat the investigationy — use more than one plant shoot” /increase the sample size (Mark FIRST TWO only) (2) (8) Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmorephysics.com 3.3 3.3.1 Cv -Irisv (2) 3.3.2 *Pupillary mechanismv - circular muscles contractY - the radial muscles relax” - the pupil constrictsv’ - less light enters the eyev (1* Compulsory mark + Any 4) (5) 3.3.3. Transparentv - to permit light to pass throughy OR it is convexY - for the minor refraction of light raysY (2) 3.3.4 -maintains the shape of the cornea Vv - supplies the lens and cornea with food and oxygenv - plays a minor role in their fraction of lightY (Mark FIRST TWO only) (2) 33.5 1” (1) 3.3.6 The lens is less convex” (1) 3.3.7 - the ciliary mi - the ciliary bo - suspensory ligame - and tension on thi ie lens¥ sion decreases - the elastic lens b (5) (18) ra 3.4 3.4.1. Maintenance of a constant internal environment within the bodyv ¥ (2) 3.4.2 (a) ADHY (1) (b) KidneyY (1) (4) Copyright reserved Please turn over

Downloaded from hlayiso.com Downloaded from Stanmoreptyysics.com 3.5 - receptor cells in the carotid arteryY in the neck are stimulated - to send nerve impulses to the medulla oblongatav - medulla oblongata stimulates breathing musclesY and heartY - breathing muscles contract more activelyY - increasing the depth and rate of breathingy - the heart beats fastery - more carbon dioxide is exhaledv - the Carbon dioxide level returns back to normal’ keeee Any (5) 3.6 3.6.1. Adrenaliny (1) 3.6.2 It converts glycogen into glucosev (1) 3.6.3. - adrenalin causes the blood vessels to dilatev since — the muscles require more bloodv — with more oxygen and glucoseY — for increased cellular respiration’ / increase breakdown of glucose - to supply additional energy” Any (4) (6) 3.7 -the thyroid gland becomes more active” - more thyroxin is secretedv’ - which increases metabolismv /cellular respiration - more heat is generated on a cold dayY (4) TOTAL QUESTION 3: 50 TOTAL SECTION B: 100 GRAND TOTAL: 150 Copyright reserved Please turn over

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