WAEC Agricultural Science 2018 past questions

Checked by the Skolra question team · Last updated 23 October 2026

Ten questions from the 2018 WAEC Agricultural Science paper, with answers and explanations. We hold 38 questions from this paper, and the Skolra app has all of them.

WAEC Agricultural Science 2018 questions and answers

1. 1.The survey equipment used for measuring angular distance is
   1. A
      Ranging pole
   2. B
      Chain
   3. C
      Theodolite
      Correct
   4. D
      Dumpy level
   Show answerHide answer

   Answer: C

   The theodolite is correct. It is the surveying instrument specially built with a rotating telescope mounted on graduated horizontal and vertical circles, so it reads off angles (angular distance) between survey lines directly in degrees and minutes.

   The other instruments listed measure different things, not angles:

   Chain is used to measure linear distance along the ground, not angles.
   Ranging pole is only used for sighting and keeping survey lines straight; it does not take any measurement itself.
   Dumpy level is used to measure differences in height/elevation between points (levelling), not angular distance.

2. 2.Vitamin K deficiency in farm animals causes
   1. A
      Infertility in breeding animals
   2. B
      Rickets and weak bone formation
   3. C
      Night blindness
   4. D
      Failure of blood to clot
      Correct
   Show answerHide answer

   Answer: D

   Vitamin K is the vitamin the liver needs to make prothrombin and other clotting factors. Without enough vitamin K, an animal's blood cannot clot properly, so even a small wound leads to prolonged or excessive bleeding (a haemorrhagic condition). This is why vitamin K is sometimes called the "clotting vitamin."

   So the correct effect of vitamin K deficiency in farm animals is the failure of blood to clot.

3. 3.A groundnut variety produces a steady yield of 350kg per hectare. What will be the yield of the variety on a 10-hectare farm?
   1. A
      3,500kg
      Correct
   2. B
      35,000kg
   3. C
      350kg
   4. D
      3,850kg
   Show answerHide answer

   Answer: A

   Working: The variety gives a steady yield of 350kg on every hectare, so to find the total yield on 10 hectares, multiply the yield per hectare by the number of hectares.

   350kg/hectare × 10 hectares = 3,500kg.

4. 4.One advantage of cross breeding is that the
   1. A
      offspring are usually weaker and less productive than either parent
   2. B
      offspring produced are genetically pure and breed true to type
   3. C
      resulting offspring combine the desirable characteristics of both parent breeds, giving hybrid vigour
      Correct
   4. D
      new breed produced requires no further selection or management
   Show answerHide answer

   Answer: C

   Cross breeding is the mating of animals from two different breeds (e.g. a local breed with an exotic breed) to produce offspring that combine the good qualities of both parents. The main advantage tested here is that the resulting offspring combine the desirable characteristics of both parent breeds — this is called hybrid vigour (heterosis), where the crossbred animal often grows faster, is more disease-resistant, or more productive than either parent alone.

5. 5.Which of the following crops is usually classified as a vegetable?
   1. A
      Tomato
      Correct
   2. B
      Cassava
   3. C
      Maize
   4. D
      Cotton
   Show answerHide answer

   Answer: A

   Tomato is the crop usually classified as a vegetable. Vegetables are herbaceous plants (or parts of plants) grown mainly for food and eaten fresh or cooked as part of a meal, usually harvested within a short growing season — examples include tomato, okra, pepper, spinach and fluted pumpkin (ugu).

   The other options are classified differently by crop type:

   Cassava is a root and tuber crop, grown for its starchy underground root, not classified with vegetables.

6. 6.Which of the following agricultural extension methods is aimed at reaching an individual farmer at a particular time?
   1. A
      Field day
   2. B
      Farm and home visit
      Correct
   3. C
      Radio broadcast
   4. D
      Group discussion
   Show answerHide answer

   Answer: B

   Farm and home visit is correct. Extension methods are grouped by the size of the audience they reach: individual methods reach one farmer at a time, group methods reach a gathered group, and mass methods reach a large, scattered audience.

7. 7.Which of the following practices does not replenish lost soil nutrients?
   1. A
      Application of farmyard manure
   2. B
      Crop rotation
   3. C
      Bush burning
      Correct
   4. D
      Green manuring
   Show answerHide answer

   Answer: C

   Bush burning does not replenish lost soil nutrients — in fact it destroys them. When vegetation and crop residues are burnt, the organic matter that would have decomposed to release nitrogen, and build up humus, is lost as ash and smoke. Burning kills soil micro-organisms that break down organic matter and fix nitrogen, exposes the bare soil to erosion and leaching, and leaves the soil poorer in nitrogen and organic matter than before.

   So among the four, only bush burning works against soil fertility instead of building it up.

8. 8.Thinning is a farm operation in which
   1. A
      diseased plants are uprooted and destroyed to prevent the spread of infection
   2. B
      excess or weak seedlings are removed from a stand to reduce overcrowding
      Correct
   3. C
      unwanted branches are cut off a plant to improve its shape and yield
   4. D
      weeds growing between crop rows are removed to reduce competition
   Show answerHide answer

   Answer: B

   Thinning is the farm operation in which excess or weak seedlings are removed from a stand to reduce overcrowding, leaving well-spaced, healthy plants with enough room, light, water and nutrients to grow properly. It is usually carried out after germination where seeds were sown too close together (e.g. maize, carrot, okra).

9. 9.Bees are regarded as the friends of the farmer because they
   1. A
      feed on and destroy harmful insect pests on crops
   2. B
      produce wax that farmers use to preserve harvested produce
   3. C
      help in decomposing dead organic matter in the soil
   4. D
      help in the pollination of farm crops, thereby increasing yield
      Correct
   Show answerHide answer

   Answer: D

   Bees are regarded as the friends of the farmer because they help in the pollination of farm crops, thereby increasing yield.

10. 10.The chemical composition of soil is mostly influenced by
    1. A
       Climate of the area
    2. B
       Slope of the land
    3. C
       Nature of the parent rock
       Correct
    4. D
       Type of vegetation cover
    Show answerHide answer

    Answer: C

    Nature of the parent rock is correct. Soil forms mainly from the weathering (breakdown) of the rock lying beneath it, called the parent material. As this rock breaks down, the minerals it contains (such as calcium, potassium, iron, phosphorus and magnesium compounds) pass into the soil. This means the chemical elements and compounds found in a soil are largely a reflection of the chemical make-up of the rock it weathered from — a soil formed from basalt will differ chemically from one formed from granite or limestone.

The questions come from past JAMB, WAEC and NECO papers. We use software to help write the answer options and explanations, and every answer is checked twice before it goes on the site. How we check

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Practise all 38 questions we hold from the 2018 paper, on a timed CBT screen

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