Life Sciences Grade 12 P1 Eastern Cape Mock 2014 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 12 SEPTEMBER 2014 LIFE SCIENCES P1 MEMORANDUM MARKS: 150 This memorandum consists of 10 pages.

Downloaded from hlayiso.com 2 LIFE SCIENCES P1 (SEPTEMBER 2014) SECTION A QUESTION 1 1.1 1.1.1 C  1.1.2 B  1.1.3 B  1.1.4 C  1.1.5 B  1.1.6 C  1.1.7 C  1.1.8 B  1.1.9 C  1.10 C  (10 x 2) (20) 1.2 1.2.1 Umbilical vein  1.2.2 Gestation  1.2.3 Multiple Sclerosis  1.2.4 Foetus  1.2.5 Chorion  1.2.6 Alien species  (6 x 1) (6) 1.3 1.3.1 A only  1.3.2 B only  1.3.3 None  1.3.4 A only  1.3.5 Both A and B (Both)  1.3.6 Both A and B (Both)  (6 x 2) (12) 1.4 1.4.1 A – Anaphase 1  B – Anaphase 2  (2) Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) LIFE SCIENCES P1 3 1.4.2 Stage A  (1) 1.4.3  Crossing over   Independent assortment of chromosomes  during metaphase (2) 1.4.4 4 (1) 1.4.5 4 (1) 1.5 1.5.1 Pancreas  (1) 1.5.2 Insulin  (1) 1.5.3 4%  (1) 1.5.4 Females  (1) 1.5.5 35–37  (1) TOTAL SECTION A: 50 Copyright reserved Please turn over

Downloaded from hlayiso.com 4 LIFE SCIENCES P1 (SEPTEMBER 2014) SECTION B QUESTION 2 2.1 2.1.1 A – Seminal vesicle  C – Cowper’s gland  (2) 2.1.2  Serves as a medium of sperm mobility   As a source of nutrients   Prevents the dehydration of sperms   Neutralises the acidity of vaginal tract  (Any 1) (1) 2.1.3 (a) Part D  (1) (b) Part E  (1) 2.1.4 Testes/part E  (1) (6) 2.2 2.2.1 (a) To make the endometrium wall thicker/more vascular  (Any 1) (1) (b) Stimulates ovulation/convert the empty follicle into a corpus luteum  (Any 1) (1) 2.2.2 Day 14  (13–15) (1) 2.2.3 The level of oestrogen decrease sharply / The level of luteinising hormone increases  (1) 2.2.4 (a) Graffian follicle  (1) (b) Corpus luteum  (1) 2.2.5 (a) Pregnancy has resulted  (1) (b) No pregnancy / leads to menstruation (1) 2.3 2.3.1 The further from the light source,  the wider the diameter of the pupil  OR The further the light source,  the diameter of the pupil becomes shorter  OR The closer the light source,  the narrower diameter of the pupil  OR Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) LIFE SCIENCES P1 5 The closer the light source,  the wider the diameter of the pupil.  OR As light intensity increases/decreases  the diameter of the pupil increases/decreases.  (2) 2.3.2  Position of the face/person   The intensity of light   Time allocated for the light source at each distance  (Any 2) (2) 2.3.3 (a) Independent factor – The position of the lamp/light source  (b) Dependent factor – Diameter of the pupil  (2) 2.3.4 Accept  /Reject (Mark the response in correspondence with hypothesis given by the learner in QUESTION 2.3.1.) (1) 2.3.5 The size (diameter) of the pupil increases  when the light intensity decreases  OR The size of the pupil (diameter) of pupil decrease  when the light intensity increases.  OR The further from the light source,  the wider the diameter of the pupil  OR The closer the light source,  the diameter of the pupil becomes smaller  (2) 2.3.6  The circular muscles  will contract  while the radial muscles  relax.   As a result the diameter of the pupil will decrease,  restricting the high intensity light entering the eye. (Max 4) (4) 2.3.7 Pupillary mechanism  (1) Copyright reserved Please turn over

Downloaded from hlayiso.com 6 LIFE SCIENCES P1 (SEPTEMBER 2014) 2.3.8 Diameter of the pupil (mm) at various distances from the light source 6 5 Diameter of the pupil in mm 4 3 2 1 0 1 2 3 4 5 6 7 Position of the Lamp Criteria for marking the graph Title of the graph (both Dependent and 2 Independent variables are included) Correct type of graph 1 Appropriate scale and label for X-axes 1 Appropriate scale and label for Y-axes 1 1 : 1 to 3 bars drawn correctly Number of bars 2 : 4 to 6 bars drawn correctly 3 : All bars correctly drawn NOTE: If the wrong type of graph is drawn, 3 marks will be lost for:  Correct type of graph  Plotting number of bars If the labels of the axes are transposed then 2 marks will be lost for:  Correct label and scale for X and Y-axes. (8) 2.4 (a) Growing different crops on the same piece of land  in different seasons so as to give the soil time to recover/replenish nutrients. (2) (b) A process by which nutrients, especially phosphorus and nitrogen become highly concentrated in a body of water,  leading to increased growth of organisms such as algae.  (2) [40] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) LIFE SCIENCES P1 7 QUESTION 3 3.1 3.1.1 Phototropism  (1) 3.1.2 Growth movement  of plant organs in response to light stimulus.  (2) 3.1.3 To provide unilateral light stimulus for the seedlings inside the box.  (1) 3.1.4 Auxins  (1) 3.1.5 When unilateral (one-sided) light rays fall on the growing tip of a seedling,  the hormone auxin  begin to move from brighter side to the darker side of the growing tip.  The accumulation of auxin in the darker side causes cells in that region to grow longer than the one in the brighter side  and leading to the bending of growing tip towards the direction of unilateral light source  (5) 3.1.6 A spontaneous upward growth of seedlings can be expected.  (1) 3.2 3.2.1 Poaching  (1) 3.2.2 The unprecedented rise in the poaching  of rhinoceros would lead to the extinction of this species  in the near future and therefore, one has to travel abroad to see the rhinoceros in captivity.  The cartoon depicts the magnitude of this illegal activity in South Africa.  The cartoon also captures our inability to control poaching effectively  and prioritise the significance of conservation.  (Any 3) (3) 3.2.3 Horn of rhinoceros  (1) 3.2.4  Safe dehorning   Harsher prison sentences   Educating people   Rhino horn poisoning so that it becomes less palatable to users  Introduce “Rhino protect treatment” where rhino horn is made valueless for the poachers as it gets injected with dye where x-ray scanners will be able detect the horn  Selling off horns from rhino who died of natural causes   Introduce a ban on rhino horn sale   Legalise international trade of the rhino horn  (Any 2) (2) 3.2.5  668 – 448 = 220  OR     (3) Copyright reserved Please turn over

Downloaded from hlayiso.com 8 LIFE SCIENCES P1 (SEPTEMBER 2014) 3.2.6 A steady increase in poaching  of the rhinoceros population of South Africa since 2010. (1) 3.3 3.3.1 Adrenalin  (1) 3.3.2 Adrenal gland  (1) 3.3.3 An endocrine gland  (1) 3.3.4  Increases the rate and depth of breathing  so that more oxygen is obtained quickly.   Causes the liver to convert more glycogen to glucose which is then released into the blood stream as a source of energy   Increases the rate of the heartbeat and the blood pressure  so that blood can be carried quickly to the skeletal muscles and brain.   Causes the blood vessels of the muscles, heart and brain to dilate so that more blood can be taken to these parts.   Causes the blood vessels of the digestive system and skin to constrict  so that less blood is sent to these parts and more blood becomes available for the heart, brain and skeletal Muscles.   Increases the metabolic rate of the cells in the brain and skeletal muscles  so that more energy is released for muscular activity and clear thought.   Increases the tone of the skeletal muscles  so that they can function more effectively.  (Any 2 x 2) (4) 3.4 3.4.1 Negative feedback mechanism (1) 3.4.2 1 Thyroid gland  2 Thyroid Stimulating Hormone  3 Thyroxin  4 Thyroxin  (4) 3.4.3 Iodine  (1) 3.4.4 Goitre  (1) (7) 3.5 Amount of CO2 released = Amount of energy source used per month x Emission factor Petrol =  Diesel =  Electricity =  Total carbon footprint =  (4) [40] Copyright reserved Please turn over

Downloaded from hlayiso.com (SEPTEMBER 2014) LIFE SCIENCES P1 9 SECTION C QUESTION 4 Capturing and transmission of sound waves at the outer ear  Sound waves which travel through the air are captured and directed by the pinna   through the auditory canal   to the tympanic membrane   causing it to vibrate.  (Max 2) Transmission of sound vibrations at the middle ear  The vibrations are transferred to the ossicles  (malleus, incus and stapes) of the middle ear.  The stapes transfers the sound vibrations on to the oval window  (Max 2) Transmission of pressure waves/vibrations at the inner ear  In the inner ear pressure waves are set up in the perilymph   of the vestibular canal in the inner ear.   The vibrations are transferred through the membrane of the middle canal  to the endolymph.   The pressure waves created in the endolymph stimulate the hair cells   of the organs of Corti.   The hair cells send impulses along the auditory nerve   to the cerebrum.   The signals received from ear are then processed and interpreted.   The pressure waves are then transferred to the tympanic canal   where they are finally absorbed by the round window.  (Max 7) (11) Role of the ear in the maintenance of balance  The ampullae  /broader bases of semi-circular canals  consist of cristae.   The three semicircular canals are positioned in three different planes   and therefore, any sudden changes in the speed and direction of body movement,   cause the endolymph to move  at least in one of the semi-circular canals.  The movement of endolymph stimulates   the cristae to generate and send impulses.   The sacculae and utriculae   consist of special receptor structures called maculae.   When the direction of the head changes,   gravitational pull stimulates   hair cells (receptors) of maculae to generate impulses.   the impulses generated from both cristae and maculae are send to cerebellum.   The cerebellum sends impulses to the muscles to restore the balance.  (Max 6) (6) Copyright reserved Please turn over

Downloaded from hlayiso.com 10 LIFE SCIENCES P1 (SEPTEMBER 2014) ASSESSING THE PRESENTATION OF THE ESSAY Criterion Relevance (R) Logical sequence Comprehensive (C) (L) Generally All information Facts are arranged All aspects required by provided is in a logical/ the essay have been relevant to the sequential order. sufficiently addressed. topic. In this essay Only information Events of hearing Learner has scored at relevant to the and balance are least half of the marks hearing and provided in the of the hearing process balance is given correct sequence. and described the (There is no function of cristae and irrelevant maculae in the information.) maintenance of balance. MARK 1 1 1 Synthesis (3) TOTAL SECTION C: 20 GRAND TOTAL: 150 Copyright reserved Please turn over

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