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GAUTENG DEPARTMENT OF EDUCATION
SENIOR CERTIFICATE EXAMINATION
PHYSIOLOGY HG
POSSIBLE ANSWERS / MOONTLIKE ANTWOORDE
OCTOBER/ OKTOBER / NOVEMBER 2005
SECTION A
QUESTION 1A
1.1 C
1.2 D
1.3 B
1.4 A
1.5 B
1.6 D
1.7 C
1.8 C
1.9 D
1.10 B
1.11 A
1.12 D
1.13 B
1.14 A
1.15 B
1.16 D
1.17 C
1.18 D
1.19 C
1.20 D
1.21 C
1.22 B
1.23 B
1.24 C
1.25 B
1.26 A
1.27 A
1.28 B
1.29 B
1.30 B 30 x 2=
(60)
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QUESTION 1B
1.31 Dura mater
1.32 Aquaduct of Sylvius
1.33 Folia/lamellae
1.34 Foramen magnum
1.35 Autonomic nervous system
1.36 Noradrenalin
1.37 Stimulus
1.38 Dendrite/afferent branch
1.39 Nodes of Ranvier
1.40 Micturition
1.41 Pancreas
1.42 Hypophysis/Pituitary gland
1.43 Neurilemma
1.44 Neuron
(14)
QUESTION 1C
1.45 Bladder - Stores urine
1.46 Ureter - Conveys urine from the kidneys to the bladder
1.47 Ejaculatory duct - Strong muscular contractions helps expel semen
during ejaculation
1.48 Cowper’s gland - Secretes alkaline mucus to neutralise acids in urethra
and vagina
1.49 Urethra - Transports urine and semen out of body
1.50 Epididymus - Maturation (10 – 14 days) of spermatozoa OR
Storage of spermatozoa until fertile
1.51 Testis - Produce spermatozoa through spermatogenesis
1.52 Penis - Transfer semen to upper part of vagina to ensure
that spermatozoa are closer to ovum
Ensures internal fertilization
(16)
TOTAL FOR SECTION A: [90]
SECTION B
QUESTION 2
2.1 2.1.1 A. Adrenaline B. Glucagon (2)
2.1.2 a) Adrenalv medullav (2)
b) Fight or Flight hormone / sympathetic activator (1)
c) – Vasodilation in skeletal and heart muscle/
vasoconstriction of gastro-intestinal tract and skin/
increase blood pressure
– Increase in oxygen content of blood/breathing rate and depth
increases so that more oxygen is inhaled
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– Heart rate and stroke volume increases, more blood with
more oxygen to muscles to produce more energy
– Pupils of eye dilate, due to contraction of radial muscles –
better vision
– More ACTH released – cope more effectively with stress
– Increased sweating to cool body
– Gastro-intestinal activity reduced as energy is needed for
skeletal muscles
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– Sphincter of bladder relaxes and the sphincter of the large
intestines contract (Any 7 of 8) (7)
2.1.3 Sympathetic nervous system (1)
2.2 Sensory nerve 1 diagram
1 heading
5 labels (7)
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2.3 2.3.1 1. Dura mater
2. Arachnoid mater
3. Pia mater
4. Posterior/Dorsal fissure
5. Ganglion/posterior root ganglion
6. Central canal
7. Ventral/anterior fissure (7)
2.3.2 – The afferent impulses from the limbs and other parts of the body
are conducted via ascending tracts to the brain.
– The efferent impulses are conducted via descending tracts in the
spinal cord to the effectors in the body and limbs.
– The sympathetic and certain parasympathetic reflex arcs have their
cell bodies in the spinal cord.
– Seat of primitive reflex actions, called spinal reflexes
– Inhibitory neurons from the brain innervate certain motor neurons
thereby stopping reflex actions from taking place. (5)
2.3.3 a) If no. 8 is damaged, the person will have no sensationv as the
sensory neuronsv are damaged. (2)
b) If no. 9 is damaged, the person will have no reactions/movementsv
as the motor nervesv are damaged. (2)
2.3.4 a) Vestibulum and the cochlea in the ear. (2)
b) This nerve has sensory branches as well as motor branches
(consists of sensory neurons as well as motor neurons). (2)
[40]
QUESTION 3
3.1 3.1.1 37,6º C (2)
3.1.2 50 or 51 units (2)
3.1.3 a) Internal body temperature droppedv between the 10 th and 25 th
minutes until it reached 37º Cv. (2)
b) Skin temperature increasedv until it reaches 37,6º Cv. (2)
c) Sweating rate decreasedv until it reaches 10 units. v (2)
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3.1.4 When the internal blood temperature decreasesv the hypothalamusv is
stimulated. Impulses are sent to the vasomotor centre in the medulla
oblongata. Impulses are sent to the smooth muscles in the walls of the
arterioles in the skinv to contractv vasoconstriction occurs.
Less warm blood flows to skinv less heat lossv through radiationv,
convectionv and conductionv.
Lower sweat productionv – less heat loss through evaporationv
Erector muscle contractsv trapping a layer of air as insulation. v More
thyroxin secretedv – more heat produced caused by higher metabolic
ratev. More adrenaline is secretedv stimulates conversion of glycogen to
glucose. v Muscle tone increasesv – shiveringv – more heat energy
generatedv. Body temperature will increase. v
(20)
3.2 The skin:
•
•
•
•
•
•
Produces melanin which protects the body against the harmful UV rays of
the sun.
Produces Vitamin D from steroids in the skin.
Acts as a secretory organ – milk, sebum, cerumen.
Waterproof layer, prevents excessive loss of water.
Cornified layer protects/prevents entry of germs and bacteria.
Cornified layer protects the body against mechanical injuries. (Any 5 of 6) (5)
3.3 a) Endothermic
4.1
Body heat is obtained from inside the body and causes the body
temperature to stay constant. (2)
b) Homeostasis
Maintenance of a constant internal environmentv for normal cell
functioningv by self-regulating mechanisms. v (3)
[40]
QUESTION 4
Graph
Strongest
Taste
Region on
tongue
Substance
causing the taste
Papilla sensing the
taste
A Salty Sides/tip Sodium Fungiform
B Sour Sides Hydrogen ions Fungiform
C Sweet Tip/front Sugars Fungiform
D Bitter Back Quinine Circumvallate (16)
4.2 4.2.1 Chemoreceptors
4.2.2 Food particles dissolve (1) in saliva. v
Substances in solution/dissolved substances. v
Stimulate the receptor cells/sensory hair cellsv in the taste budsv which
convert the stimulus into an impulse/triggers series of impulsesv
conducted via sensory neuronsv to temporal lobe of cerebrumv where
sensation of taste rises/ interpreted. v
any
(1)
(8)
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4.3 Filliforme papillae (1) is sensitive to touch (1) e.g. hair. (2)
4.4 4.4.1 a) Between measurements 1 and 2
b) Between measurements 5 and 6 / 6 and 7.
(1)
(1)
4.4.2 a) At measurement 4 (1)
b) At measurement 8 (1)
4.4.3 The bright light of the torch was the same distance from the eye.
4.4.4 The closer the bright light source is to the eye
– the smaller the diameter of the pupil.
– Less is the light allowed into the eye.
– The more protected is the sensitive retina on the inside. (3)
4.4.5 Acromatosis/total colour blindness/v no sensitivity to colour, only shades of
grey, black and whitev.
Red-green colour blindnessv – red or green cones are missingv
cannot distinguish between red and greenv see either red or greenv. (5)
[40]
QUESTION 5
5.1
COLUMN A
COLUMN B
NAME OF RECEPTOR
PART OF BRAIN
1. Cones G
2. Rods G
3. Crista H
4. Macula H
5. Organ of Corti C
6. Corpuscles of Ruffini /
E/F
Free nerve endings
(12)
5.2 5.2.1 Cerumen/wax glandsv – secretes cerumen/waxv
– prevents skin from drying outv
– pungent smell repels insectsv (4)
5.2.2 Ball of cerumen accumulates in front of tympanumv and inhibits the
transfer of sound waves/prevents it from vibrating. (2)
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Answer Question 6 or Question 7.
QUESTION 6
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5.3 Specialized cells in the afferent arteriole/jutaglomerular cellsv
respond to the decrease in sodium concentrationv
or drop in blood pressure/blood flowv.
or sympathetic stimulationv
by secreting the enzyme reninv which causes the production of angiotensinv
which stimulates the secretion of aldosteronev by the adrenal cortexv
aldosterone travels through the bloodv to the distal convoluted tabulev
where it stimulates the reabsorbtion of sodium ionsv
chlorine ions follow passivelyv into the peritubular capillariesv
water follows passively/by osmosisv
increase in blood pressurev. (12)
5.4 5.4.1 Secondary oocytev and the first polar bodyv. (2)
5.4.2 Spermatozoa reaches the ovum in the fallopian tubev
Acrosomev will secrete hydrolytic enzymesv that will dissolve the
Zona pellucidav / follicle cells / corona radiate.
Only the head of the spermatozoa enters the ovumv
The tail is discarded ofv.
The fertilization membranev prevents other sperms from entering.
The second meiotic divisionv takes place to form the ovum and 3 polar
bodiesv which disintegrate.
Fusion of the nuclei of the sperm and ovum takes place to form a zygote
with 46 chromosomes (2n)v. (Any 8 of 11) (8)
SECTION C
TOTAL FOR SECTION B: [160]
6.1 1. Posterior Hypophysis/Neurohypophysis
2. Anterior Hypophysis/Adeno Hypophysis (2)
6.2 3. Oxtytocin – release and the flow of milk from the mammary glands
4. Prolactin – stimulates milk production (4)
6.3 Oxytocin ( √) is not only responsible for the flow of milk but also for the
contraction of the uterus. ( √). While breastfeeding the secretion of oxytocin
is stimulated, ( √) resulting in the contraction of the uterus back to its normal
size. ( √)
(4)
6.4 9. Fallopian tube
10. Infundibulum
11. Fimbriae
13. Vagina (4)
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6.5 a) Endometrium
Myometrium
Perimetrium
b) Fundus
Corpus
Cervix (6)
6.6 ICSH ( √) – Stimulates the cells of Leydig (Intestitial cells) ( √) to secrete
testosterone. ( √) (3)
6.7 Vasectomy, Male condom, Withdrawal method, Male pill. (Any 3) (3)
6.8 6.8.1 If fertilization takes place:
LH concentration is high (1) – to maintain the corpus luteum (1)
Progesterone concentration is high (1) – secreted by the corpus luteum (1)
– to maintain the endometrium (1)
– stop uterus from contraction/abortion/miscarriage (1)
Oestogen concentration is high (1) – prepares breasts for milk
production (1) prepares endometrium for implantation (1) inhibits
FSH secretion/Low FSH (1) to prevent a Graafian Follicle from
developing (1). (Any 10) (10)
6.8.2 Just after ovulation, the remains of the Graafian Follicle from the Corpus
Luteum (1) which secretes progesterone (1) and oestrogen (1).
These two hormones maintain the uterus (1) during pregnancy.
After 3 months, the placenta will be fully developed (1) and will then
secrete these two hormones (1). Then the ovaries are not needed to fulfil
this function anymore and can be removed.(1) (Any 6) (6)
6.9 The testis
Two oval glands (1) carried in the scrotum (1).
Fibrous connective tissue divides testis in lobules (1)
In each lobule are highly convoluted tubules ( √)
– the seminiferous
tubules (1) – which unite to form straight tubules (1) – which unite to form
straight tubules (1) – which is their turn unite to form the rete testis (1) –
that joins to enter the epididymis (1). (Any 5 of 8) (8)
[50]
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QUESTION 7
7.1 The kidney regulates the water content of the blood (osmoregulation)
Regulates the pH of the blood/acid - base balance.
Regulates the sodium content of the blood/regulates electrolytes.
Excretes metabolic waste/nitrogenous waste. (4)
7.2 7.2.1 70 mmHg – 14 mmHg = 56 mmHg √√
(2)
7.2.2 125 ml/min √ x 60 √ = 7 500 ml/hour (3)
7.2.3 a) 1 ml/min x 60 √ x 24 √ = 144 ml/day √ = 1,44 l/day √
(4)
b) On a hot summers day a person loses more water through
sweat √, thus less urine will be produced. √
(2)
c) When the body becomes dehydrated √ /
when body loses too much water through sweat
the osmotic pressure in the blood rises √
osmoreceptors √ in the hypothalamus √ are stimulated
causes an impulse to be sent √ to the neurohypophysis √
which is stimulated to secrete ADH √.
ADH travels with the blood √ to the kidney.
The collecting ducts √ and distal convoluted tubules√
become more permeable √ to water.
More water will be reabsorbed √ by osmosis√
into the peritubular capillaries√
increasing the blood volume/ decreasing the osmotic pressure√
(Any 11 of 15) (11)
d) Proteins, white-blood cells, erythrocytes, platelets. (Any 3 of 4) (3)
e) The basements membrane of the capillaries is thin√
The single √ endothelial layer has many pores √
The podocytes in the Bowman’s capsule has filter slits √ (Any 3 of 4) (3)
7.2.4 125 ml/min – 25 ml/min = 100 ml of water per minute √ passively √
reabsorbed in the proximal convoluted tubule. √
(3)
7.2.5 A. No food
Low Glucose level in blood√
Low cellular respiration √ – not enough energy/ATP√
Feels tired/weak √. Also influences osmotic pressure √
(Any 3)
Low ion concentration√
Certain ions, namely sodium, potassium. Chloride, bicarbonate
and phosphate must be present for proper cell functioning
(At lease 2 examples) (2)
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Nitrogen waste√
Due to the absence of glucose, the body uses proteins (of muscles) √ and
the metabolism thereof will increase waste products like urea, creatinine,
which will become toxic √
(Any 2)
B. No water
Water is needed for metabolic reactions √ in cells, for transport medium, √
affects the osmotic potential of fluids.
Hormone concentration will be influenced√
Water is needed to control temperature for effectiveness of enzymes and
proteinsv. (Any 2)
C. When he suffocates himself
Low Oxygen concentration √ – low cellular respiration rate –
energy released slower √
(2)
High Carbon dioxide √ concentration
reacts with water to form carbonic acid √ which lowers the pH of the tissue
fluid √
(Any 2)
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pH √ level drops below 7,0 due to CO 2 denature enzymes√
metabolic processes cease. (2) (15)
TOTAL FOR SECTION C: [50]
TOTAL: 300
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