AGRICULTURAL SCIENCES
GRADE 12 
NSC EXAMS
PAST PAPERS AND MEMOS JUNE 2019

MEMORANDUM 

SECTION A  
QUESTION 1 
1.1
1.1.1 B ✔✔ 
 1.1.2 C ✔✔ 
 1.1.3 D ✔✔ 
 1.1.4 A ✔✔ 
 1.1.5 D ✔✔ 
 1.1.6 C ✔✔ 
 1.1.7 A ✔✔  
 1.1.8 D ✔✔ 
 1.1.9 A ✔✔ 
 1.1.10 B ✔✔ (10 x 2) (20)   
1.2
1.2.1 None ✔✔ 
 1.2.2 Both A and B ✔✔ 
 1.2.3 None ✔✔ 
 1.2.4 A only ✔✔ 
 1.2.5 B only ✔✔ (5 x 2) (10)   
1.3
1.3.1 Bloating/Bloat ✔✔ 
 1.3.2 Osteomalacia ✔✔ 
 1.3.3 Diagnosis ✔✔ 
 1.3.4 Superovulation ✔✔ 
 1.3.5 Hermaphroditism ✔✔ (5 x 2) (10)   
1.4
1.4.1 Proteolytic ✔ 
 1.4.2 Endemic ✔ 
 1.4.3 Mitochondria/Mitochondrion ✔ 
 1.4.4 Lactation ✔ 
 1.4.5 Sterility ✔ (5 x 1) (5)   

 TOTAL SECTION A: 45  

SECTION B  
QUESTION 2: ANIMAL NUTRITION 
2.1 A representation of the alimentary canal of a farm animal  
2.1.1 Identification of A and C  

• A: Oesophageal groove ✔ (1) 
• C: Omasum ✔ (1)  

 2.1.2 Explanation of the main function of part A in DIAGRAM 1  

•  It directs the milk to the abomasum ✔ (1)   

 2.1.3 Identification of the true stomach  

•  D ✔ (1)   

 2.1.4 Justification for not feeding urea or biuret to young ruminants 

• Its fore-stomachs (rumen, reticulum and omasum) are still  underdeveloped ✔ with very few or no micro-organism to assist in   digesting ✔ urea and biuret. (2)   

2.2 The part of the alimentary canals of farm animals  
 2.2.1 Identification of A  

• A: Villi / Villus ✔ (1)   

 2.2.2 TWO reasons visible to support adaptation of villi for absorption

• There are many folds that increase surface area for absorption ✔ 
• The folds are covered with thousands of villi which increases  surface area for absorption ✔ 
• Each villus is covered with micro-villi which further increases  surface area ✔ 
• Presence of blood vessels ✔ 
• Presence of lymphatic vessels ✔ (Any 1 x 2) (2)   

2.3 The name of the diseases caused by a deficiency of vitamin/mineral in  lambs 
 2.3.1 Swayback / Anaemia ✔ (1)   
 2.3.2 Muscular dystrophy / White muscle / Stiff lamb disease ✔ (1)  
2.4 Energy flow diagram  
 2.4.1 Energy type represented by A and B  

•  A: Digestible energy / DE ✔ 
• B: Metabolised energy / ME / Metabolisable ✔ (2)  

 2.4.2 (a) The amount of energy left for production and maintenance in   joules  

•  Net energy is 40% (Net) of 1 250 j (Gross Energy) 
•  Net energy =   40  x 1 250 j ✔ 
                         100 
  = 500 j ✔ (2) 

 (b) Total energy losses in kilojoules 
 Total energy losses = (30%) + (5%) + (5%) + (20%) = 60% of    1 250 j = 750 j ✔ 
 = 750 j = 0,75 Kj ✔ (3) 
  1 000✔ 

2.5 The Pearson square
 2.5.1

• (Maize meal): 8%                                         23 ✔ (parts) (39 – 16 = 23)  
                         
  (Soya bean meal): 39%                             8 ✔ (parts) (16 – 8 = 8) 
  The ratio of maize meal to soya bean meal is 23 : 8 ✔ (4)  

 2.5.2 Formulation of 1 500 kg swine ration:  

•  The ratio into which feeds should be mixed is 23 : 8 (maize meal to  soya bean meal) = 23 + 8 = 31 ✔(5)  

2.5.3 Reason for a high protein requirement in piglets  

• Growth and production ✔
• Provision of antibodies for immunity against diseases ✔ 
• Repairing of body tissues ✔ (Any 2 x 1) (2)  

2.6 Fodder-flow:  
 2.6.1 The number of months during which there will be less feed  available than required by the animals  

• 5 months ✔ (1)   

 2.6.2 Calculation of the surplus amount of feed during the month of  October in kilograms (kg)  

•  55 tons – 20 tons = 35 tons ✔ 
• 35 tons x 1000 ✔ = 35 000 kg ✔ (3)   

 2.6.3 TWO strategies a farmer can apply to make sure that the required  feed balances feed available  

•  Culling ✔ 
• Controlled calving ✔ 
• Producing more food at particular times ✔ 
• Storage ✔ (Any 2 x 1) (2)  [35] 

QUESTION 3: ANIMAL PRODUCTION, PROTECTION AND CONTROL
3.1 Animal production systems  
 3.1.1 Identification production systems  

• FARM A: Intensive production system ✔ 
• FARM B: Extensive production system ✔ (2)  

 3.1.2 Justification for QUESTION 3.1.1  
FARM A: Intensive production system  

• Many animals in small area (high density) ✔ 
• High capital investment ✔ 
• Labour intensive ✔ 
• Use of sophisticated technology ✔ (Any 1)  (1)

FARM B: Extensive production system  

•  Few animals occupied a large area (low density) ✔
• ∙ Low capital investment ✔ 
• Very few labour employed ✔ 
• Minimal or no technology use ✔ (Any 1) (1)

3.1.3 Examples of an intensive production system  

• Piggery / Broilers / Layers / Sheep / Boer goats ✔ (Any 1) (1)  

 3.1.4 Differentiation between: Subsistence farming:  

• Farming in small quantities to meet the needs of their families and  sell the surplus ✔ 

Commercial farming:  

• Farming in large quantities in order to make profit ✔ (2)  

3.2 Scenario on animal body temperature
 3.2.1 Indication of the situation at points A and B  
Point A:  

• Cold stress / extremely cold / very cold ✔  (1)

Point B:  

• Heat stress / extremely hot / very hot ✔ (1)

3.2.2 Description of how the situation affects feeding and milk  production in dairy cows  
Point A:  

• They eat more to keep themselves warm ✔ resulting in low milk   production ✔ 

Point B:  

• Animals eat less feed ✔ and milk production decreases ✔ (4)  

 3.2.3 Recommended measures:  
Point A:  

•  Provision of shelter / heaters / air conditioners ✔ (Any 1)

Point B:  

• Provision of shelter / air conditioners / misting 
• Provision of enough water ✔ (Any 1) (2)   

3.3 Completion of the table  

• A: Elastrator with elastic rings / knife / blade ✔ 
• B: Ear tag pliers / Ear tag applicator ✔ 
• C: Elastrator with elastic rings ✔ (3)   

3.4 Scenario 
 3.4.1 Micro-organism responsible for the disease  

• Bacteria ✔ (1)   

 3.4.2 Statement stating that Bovine TB is a zoonotic diseases 

• It can be transmitted from animals to humans as well as to other   animals ✔ (1)   

 3.4.3 TWO examples of zoonotic diseases  

• Anthrax ✔ 
• Rabies ✔ 
• Ringworm ✔ (Any 2) (2)   

 3.4.4 TWO symptoms of animals with TB  

• Respiratory tract problems / increased rate of breathing ✔ 
• Pneumonia symptoms ✔ 
• Chronic cough ✔ 
• Fever ✔ (Any 2) (2)   

 3.4.5 TWO methods to prevent and control the spread of TB 

• Disinfecting of premises ✔ 
• Vaccination ✔ 
• Quarantine ✔ 
• Eradication programme ✔ (Any 2) (2)  

 3.4.6 Table:  
Reported cases of improvement in TB infections presented as a  percentage for six years  

Criteria for marking  

• Correct heading/title ✔ 
• Populated table ✔ 
• Labelling: Years and Infections improvement ✔ 
• Data correctly captured in both columns of the table ✔ 
• Correct units: Percentage (%) ✔ (5)

3.5 TWO preventative /control measures of internal parasites  

• Good management / rotational grazing / avoid wet areas ✔ 
• Good nutrition ✔
• Use of feeders ✔ 
• Provision of clean water ✔ 
• Prevent overstocking ✔ 
• Separate young and adult animals ✔ 
• Strict hygiene / Strict sanitary measures / removal of dung ✔ 
• Breeding resistant animals ✔ 
• Deworming ✔ (Any 2) (2)

3.6 TWO roles of state in animal protection  

• Quarantine services ✔ 
• Enforce legislation ✔ 
• Movement permits ✔ 
• Import bans ✔ 
• Veterinary services ✔ 
• Importation of vaccines ✔ 
• Research ✔ (Any 2) (2)  [35]   

QUESTION 4: ANIMAL REPRODUCTION 
4.1 The reproductive system of a cow
 4.1.1 Identification of parts  

• G: Infundibulum ✔ 
• F: Oviduct / Fallopian tubes ✔ 
• B: Vulva ✔ (3)  

 4.1.2 Matching functions with the letter  

1.  E ✔
2. C / B ✔
3. D ✔ (3)  

 4.1.3 Name and letter of the part  

• Clitoris: ✔ A ✔ (2)  

4.2 Sperm morphology
 4.2.1 Identification  

• E ✔ (1)  

 4.2.2 Naming of the process  

• Spermatogenesis ✔ (1)  

 4.2.3 Explanation of how sperm cells A and G can cause infertility in  a bull  

• A: The sperm cannot move to the point of fertilisation ✔ (1) 
• G: The sperm cannot fertilise the egg cell ✔  (1) 

4.2.4 TWO characteristics of good quality semen  

• It must be viable ✔ 
• Thick whitish to yellow fluid ✔
• It must have normal morphology ✔ 
• Should have no odour ✔ 
• Must have good sperm concentration ✔ 
• Correct pH ✔ 
• High motility rate ✔ (Any 2) (2)  

4.3 Oestrus cycle graph
 4.3.1 Name of the hormone labelled C  

• Progesterone ✔ (1)  

 4.3.2 Indication of the stage of oestrus  

• Di-oestrus ✔ 

Reason  

• It is the longest / it lasts longer ✔ 
• High levels of progesterone ✔ (Any 2) (2)  

 4.3.3 Process represented by A  

•  Ovulation ✔ (1)  

 4.3.4 TWO visible signs of a cow on oestrus  

• Vulva is swollen with reddish mucus membranes ✔ 
• Mucus strings visible from the vulva ✔ 
• Jumps on other cows / allows other cows to jump on her ✔ 
• Scratch marks and dirt on the side and back ✔ 
• Allows mating with the bull ✔ (Any 2) (2) 

4.4 Re-arranged stages of mating  

• Erection of the penis ✔ 
• Mounting ✔ 
• Gaining intromission into the vagina ✔ 
• Ejaculation of semen into vagina ✔ (4)

4.5 Table of different processes  

1. 2 ✔
2. 3 ✔
3. 1 ✔ (3)  

4.6 Stages of parturition 
 4.6.1 Stages of parturition  

• A: Preparatory stage ✔
• D: Ejection stage ✔ (2)  

 4.6.2 TWO visible signs of parturition  

• Restlessness / walking around ✔ 
• Urinates and defecates often ✔ 
• Cow isolates itself ✔ 
• Vulva enlarges ✔ 
• String of mucus hangs from the vulva ✔ 
• Teats tight and swollen / milk drops ✔ (Any 2) (2)

4.7 Milk production graph  
 4.7.1 Name of the graph  

•  Lactation curve / Milk production curve ✔ (1)  

 4.7.2 Identification of the range of days  

•  30 to 60 days ✔ (1)  

 4.7.3 TWO factors influencing the production of milk during the peak  period  

• Age of cow ✔ 
• Pregnancy inhibits milk production ✔ 
• Increased levels of oestrogen ✔ 
• Climatic conditions ✔ 
• Proper nutrition ✔ 
• Number of times the cow is milked ✔ (Any 2) (2)  [35]  

 TOTAL SECTION B: 105 
GRAND TOTAL: 150