PREPARATORY EXAMINATION

Transcription

1 PREPRTORY EXMINTION GRE 12 LIFE SIENES P1 SEPTEMER 2016 MRKS: 150 TIME: 2½ HOURS This question paper consists of 16pages.

2 Life Sciences P1 2 FS/September 2016 INSTRUTIONS N INFORMTION Read the following instructions carefully before answering the questions nswer LL the questions. Write LL the answers in the NSWER OOK. Start the answers to EH question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. o LL drawings in pencil and label them in blue or black ink. raw diagrams, flow charts or tables only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. o NOT use graph paper. You may use a non-programmable calculator, protractor and a compass where necessary. Write neatly and legibly.

3 Life Sciences P1 3 FS/September 2016 SETION QUESTION Various options are provided as possible answers to the following questions. hoose the answer and write only the letter ( to ) next to the question number (1.1.1 to ) in the NSWER OOK, for example The type of development in birds where the young birds can move soon after hatching is Precocial development ltricial development Ovipary Ovovivipary Which ONE of the following is controlled by a negative feedback mechanism in the human body? hanges in the speed and direction of the body olour vision Water content The activities of the right side of the body being controlled by the left hemisphere elow is the list of events that occur during a human reproductive cycle. (i) irth (ii) Ovulation (iii) Implantation (iv) Fertilisation Which ONE of the following represents the correct sequence of events? (i), (ii), (iii), (iv) (ii), (i), (iv), (iii) (ii), (iv), (iii), (i) (iv), (iii), (i), (ii) Older people are seen to hold books at arm's length when they are reading, because the refractive power of the lens has decreased with age. refractive power of the lens has increased with age. lens has become less transparent with age. eyeball has become larger with age.

4 Life Sciences P1 4 FS/September The list below refers to changes that occur in the human body. (i) Interpretation of a bad smell (ii) ecreasing the size of the pupil (iii) ontrol co-ordination of muscles when walking (iv) ecreasing the heart-beat Which of the above can be considered as functions of the autonomic nervous system in the human body? (i), (iii) and (iv) (ii) only (ii) and (iv) (i), (ii), (iii) and (iv) Eutrophication is a process in which contaminated water is recycled. algae grows uncontrollably in the river. water is stored and later used for irrigation. indigenous forests are replaced by commercial tree plantations Sensory information that is sent to the cerebellum is used to initiate voluntarily movement. co-ordinate motor movement. provide conscious information of muscular movement. control reflexes of the gut and the blood system Which ONE of the following occurs during meiosis? haploid cell gives rise to two haploid cells diploid cell gives rise to two haploid cells haploid cell gives rise to four haploid cells diploid cell gives rise to four haploid cells The homeostatic function of the kidney can be affected by damage to the hypothalamus because the blood flow to the kidney increases. levels of glucose drop drastically. cellular metabolism increases. hypophysis/pituitary gland would not be able to secrete H.

5 Life Sciences P1 5 FS/September Vivipary and ovovivipary are similar in that internal fertilisation occurs. external fertilisation occurs. the egg is protected by a shell. the egg has no covering. (10 x 2) (20) 1.2 Givethe correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.7) in the NSWER OOK disorder of the eye in which the cornea is unevenly curved and prevents the proper focusing of light on the retina The transparent membrane protecting the cornea Specialised cells which transmit nerve impulses The part of the ear which traps and directs sound waves to the auditory canal Species that no longer exist on Earth The structure in the amniotic egg used for gaseous exchange and the storage of waste products The fatty layer that insulates the axon of a neuron (7 x 1) (7) 1.3 Indicate whether each of the statements in OLUMN I applies to ONLY, ONLY, OTH N ornone of the items in OLUMN II. Write only, only, both and,ornone next to the question number (1.3.1 to 1.3.4) in the NSWER OOK. OLUMN I auses a decrease in the ph of the blood disorder of the human nervous system that causes memory loss part of the ear where sound stimuli are converted to nerve impulses Planting the same crop type every year on the same piece of land. OLUMN II : Excess carbon dioxide : Excess glucose : lzheimer's disease : Multiple sclerosis : Semi-circular canals : Oval window : rop rotation : Monoculture (4x2) (8)

6 Life Sciences P1 6 FS/September The diagram below represents an animal cell in a phase of meiosis Identify part: (a) (b) State whether the phase of meiosis shown above is a part of Meiosis I or Meiosis II Name the process visible in the diagram that took place that contributes to genetic variation How many: (a) (b) (c) hromosomes are present in the cell above? hromosomes will be present in each cell at the end of meiosis? aughter cells will be present at the end of meiosis? Name the: (a) (b) PROESS that makes the chromosomes double stranded. MOLEULES involved that makes the chromosomes double stranded. (9)

7 Life Sciences P1 7 FS/September The diagram below represents a part of the central nervous system Name the part of the neuron marked Name: (a) The microscopic gap encircled marked as.

8 Life Sciences P1 8 FS/September 2016 (b) (c) The importance of. TWO types of neurons involved at. (2) Name the root through which the impulse will leave the central nervous system to reach the effector. (6) TOTL SETION : 50

9 Life Sciences P1 9 FS/September 2016 SETION QUESTION The diagram below represents the human male reproductive system Identify parts: (a) (b) E Give the LETTER and the NME of the part: (a) (b) Where mature spermatozoa are temporarily stored. Where the male hormone is produced. (2) (2) Explain the consequences to reproduction if part is surgically cut and the ends are sealed. (3) (9)

10 Life Sciences P1 10 FS/September The diagram below illustrates an oat seedling and a graph which shows the distribution of the plant growth hormone auxin, characterised mainly by its ability to stimulate cell elongation, in an oat seedling (venasativa) Germinating Seed Growing Root Oat Seedling Relative uxin oncentration [dapted fromthe Plant Hormones: iochemistry and Metabolism] Give TWO specific areas in a plant where cell elongation occur. (2) Suggest a reason why there is a marked difference in the relative auxin concentration between and the growing root escribe the trend of the auxin concentration in. (3)

11 Life Sciences P1 11 FS/September 2016 The germinating seed is positioned horizontally as illustrated. Growing Root What will happen to the growing root? Explain your answer in QUESTION (4) (11) 2.3 Thyroid disorders are caused by the abnormal secretion of thyroxin What is the abnormality referred to when the secretion of thyroxin goes beyond the normal levels? Explain what influence it will have on the body mass of a person if too much thyroxin is secreted. (2) Which hormone controls the level of thyroxin secretion in the human body? escribe the interaction between thyroxin and the hormone mentioned in QUESTION if the concentration of thyroxin goes higher than the normal level. (4) (8) 2.4 Explain the role of the adrenal glands in bringing about changes to the blood vessels in the human skin. (3)

12 Life Sciences P1 12 FS/September Read the extract below. IETES TRETMENT N MNGEMENT Two forms of diabetes are found in humans namely type I and type II. With type 1 diabetes, the body's immune system mistakenly sees the insulin-producing cells in the pancreas as foreign, and destroys them. People with type II diabetes are able to produce some of their own insulin. Often, it's not enough. Overeating, especially of foods rich in sugar, causes repeated stimulation of the pancreas, which responds by secreting large amounts of insulin. The excess insulin decreases the target cells' ability to respond to insulin. Treatment focuses on diet and exercise. [Source: Explain the consequence for TYPE I diabetics, when their immune system destroys their insulin-producing cells. (2) Give TWO target cells in the human body whose ability to respond to insulin can decrease. (2) Name ONE body fluid that can be used to test for the presence of excess glucose in the body. (5) 2.6 escribe how the body is able to increase heat loss during a hot day. (4) [40]

13 Life Sciences P1 13 FS/September 2016 QUESTION In the run-up to the hosting of the World up Soccer in 2010, hosting cities were confronted with a large increase in waste such as construction waste and domestic waste. The pie chart below shows data on 183 tons of waste collected in Johannesburg. PIE HRT SHOWING % OF WSTE OLLETE T WORL UP VENUES IN 2010 IN JOHNNESURG 20% Paper 35% Plastic 13% ans 32% Glass [Source: The list below gives an indication of the time it takes for some types of waste (garbage) to decompose in the environment. TYPES OF WSTE TIME TO EOMPOSE (YERS) Glass 1 million years Plastic beverage bottles 450 years Plastic bags years ans years Paper 6 weeks [Source: Which component of the waste in Johannesburg is decomposed in the shortest time? Give a possible reason for your answer in QUESTION

14 Life Sciences P1 14 FS/September alculate how many tons of glass was recovered in the city of Johannesburg. Show LL working. (3) Suggest TWO possible reasons why you think the city of Johannesburg should have banned the use of glass at their venues during the World up Soccer Tournament. (2) Explain ONE reason why open dump sites (landfills) near residential areas pose a risk to humans. (2) Explain TWO reasons why recycling is important. (4) (13) 3.2 eforestation is the permanent removal of trees in large numbers Suggest TWO reasons for deforestation. (2) Explain TWO consequences of deforestation for the ecosystem. (4) (6) 3.3 n investigation was done to determine the change in the size of the pupil at various distances from a light bulb. The procedure was as follow: lady sat in a dark room with her left eye covered. bright electric light bulb was switched on for a period of 20 seconds. fterwards the diameter of the pupil of the lady's right eye was measured. The same procedure was repeated every time at a different distance from the light bulb, at one-minute intervals between each measurement In this investigation, identify the: (a) (b) ependent variable Independent variable

15 iameter of pupil (mm) Life Sciences P1 15 FS/September 2016 The results obtained are shown in the graph below. 7 HNGE IN PUPIL SIZE T VRIOUS ISTNES FROM LIGHT UL istances (arbitary units) etween which TWO adjacent distances did the largest decrease in the size of the pupil take place? t what distance was the electric bulb the furthest from the lady? Explain your answer in QUESTION (3) escribe why the investigator allowed one-minute intervals between each measurement. (2) How can the reliability of the investigation be improved? (10)

16 Life Sciences P1 16 FS/September The diagram below represents a part of a human ear Label part Name the receptors that are found in part To which part of the central nervous system will the impulses formed in part go? Explain the result if the structures marked are fused. (3) (6) 3.5 escribe the structure and function of the peripheral nervous system. (5) [40] TOTL SETION : 80

17 Life Sciences P1 17 FS/September 2016 SETION QUESTION 4 escribe the development of the Graafian follicle until it becomes a corpus luteum during the menstrual cycle, describe oogenesis and also explain how another Graafian follicle is prevented from forming in the case of pregnancy. ontent: Synthesis: (17) (3) (20) NOTE: NO marks will be awarded for answers in the form of flow charts, tables or diagrams. TOTL SETION : GRN TOTL: