Grade 8 PECTAA Science Model Paper 2026-27 - English Medium

1. Animals contribute to the oxygen and carbon cycles in an ecosystem through (1.00 marks)

1. Reproduction
2. Digestion
3. Respiration
4. Plantation

Correct answer: C — Respiration

2. Which gas is required for aerobic respiration in most animals? (1.00 marks)

1. Methane
2. Nitrogen
3. Oxygen
4. Evaporation

Correct answer: C — Oxygen

3. The main reason for species to become endangered is (1.00 marks)

1. Ozone depletion
2. Plantation
3. Habitat destruction
4. Evaporation

Correct answer: C — Habitat destruction

4. The reason for the increase in carbon dioxide in the air is (1.00 marks)

1. Evaporation
2. Transpiration
3. Deforestation
4. Plantation

Correct answer: C — Deforestation

5. The biological process that converts atmospheric nitrogen into a usable form is (1.00 marks)

1. Nitrification
2. Denitrification
3. Nitrogen fixation
4. Evaporation

Correct answer: C — Nitrogen fixation

6. Which structure in a plant cell is responsible for photosynthesis? (1.00 marks)

1. Mitochondria
2. Chloroplast
3. Nucleus
4. Ribosome

Correct answer: B — Chloroplast

7. The process by which water moves through a plant and evaporates from leaves is called: (1.00 marks)

1. Respiration
2. Transpiration
3. Osmosis
4. Diffusion

Correct answer: B — Transpiration

8. Which hormone lowers blood glucose by helping cells take up glucose? (1.00 marks)

1. Insulin
2. Adrenaline
3. Thyroxine
4. Estrogen

Correct answer: A — Insulin

9. The main function of red blood cells (RBCs) is to: (1.00 marks)

1. Fight infection
2. Transport oxygen
3. Clot blood
4. Produce hormones

Correct answer: B — Transport oxygen

10. Which part of the brain controls voluntary muscle movements? (1.00 marks)

1. Cerebellum
2. Medulla oblongata
3. Cerebrum
4. Hypothalamus

Correct answer: C — Cerebrum

11. Which statement best defines a mutation? (1.00 marks)

1. Gene duplication
2. Change in DNA sequence
3. Cell division
4. Protein synthesis

Correct answer: B — Change in DNA sequence

12. Which organelle is known as the “powerhouse” of the cell? (1.00 marks)

1. Golgi apparatus
2. Lysosome
3. Mitochondria
4. Endoplasmic reticulum

Correct answer: C — Mitochondria

13. Which type of nuclear division produces two genetically identical nuclei in a typical body cell? (1.00 marks)

1. Meiosis
2. Mitosis
3. Binary fission
4. Budding

Correct answer: B — Mitosis

14. Which microorganism is used to produce ethanol by fermentation of sugars? (1.00 marks)

1. yeast
2. bacteria
3. algae
4. protozoa

Correct answer: A — yeast

15. Which enzyme is used in PCR (Polymerase Chain Reaction) to amplify DNA? (1.00 marks)

1. DNA polymerase
2. ligase
3. restriction enzyme
4. helicase

Correct answer: A — DNA polymerase

16. Which genetically engineered food contains beta-carotene, a precursor of vitamin A? (1.00 marks)

1. Golden Rice
2. Vitamin C wheat
3. Vitamin D maize
4. Vitamin B corn

Correct answer: A — Golden Rice

17. Which element belongs to Group 1 (alkali metals) in the periodic table? (1.00 marks)

1. sodium
2. magnesium
3. aluminum
4. chlorine

Correct answer: A — sodium

18. In genetic engineering, which vector is commonly used to transfer genes into plants? (1.00 marks)

1. Ti plasmid
2. bacteriophage
3. cosmid
4. retrovirus

Correct answer: A — Ti plasmid

19. The property of elements in the same period of the periodic table is that they have the same: (1.00 marks)

1. number of electron shells
2. atomic number
3. valence electrons
4. chemical reactivity

Correct answer: A — number of electron shells

20. Which metalloid is widely used as a semiconductor in electronic devices? (1.00 marks)

1. silicon
2. carbon
3. sulfur
4. phosphorus

Correct answer: A — silicon

21. Which of the following is a balanced chemical equation for the combustion of propane? (1.00 marks)

1. C3H8 + O2 → CO2 + H2O
2. C3H8 + 5O2 → 3CO2 + 4H2O
3. C3H8 + 3O2 → 3CO2 + H2O
4. 2C3H8 + 7O2 → 6CO2 + 8H2O

Correct answer: B — C3H8 + 5O2 → 3CO2 + 4H2O

22. In electrolysis of water, which gas is produced at the anode? (1.00 marks)

1. hydrogen
2. oxygen
3. nitrogen
4. carbon dioxide

Correct answer: B — oxygen

23. Which element belongs to Group 17 (halogens) in the periodic table? (1.00 marks)

1. fluorine
2. sodium
3. magnesium
4. neon

Correct answer: A — fluorine

24. The reactants in a chemical equation are written on which side of the arrow? (1.00 marks)

1. right
2. left
3. top
4. bottom

Correct answer: B — left

25. Which law states that mass is neither created nor destroyed in a chemical reaction? (1.00 marks)

1. Law of definite proportions
2. Law of conservation of mass
3. Law of multiple proportions
4. Avogadro’s law

Correct answer: B — Law of conservation of mass

26. In alkaline batteries, which electrolyte is commonly used? (1.00 marks)

1. sulfuric acid
2. potassium hydroxide
3. hydrochloric acid
4. acetic acid

Correct answer: B — potassium hydroxide

27. Which substance is commonly used to treat iron-deficiency anemia? (1.00 marks)

1. Iron salts
2. Calcium salts
3. Potassium salts
4. Iodine salts

Correct answer: A — Iron salts

28. A block is initially at rest. Which pair of horizontal forces gives zero resultant force? (1.00 marks)

1. 15 N left; 15 N right
2. 10 N left; 20 N right
3. 25 N left; 20 N right
4. 30 N left; 10 N right

Correct answer: A — 15 N left; 15 N right

29. For a constant force parallel to motion, work equals force multiplied by: (1.00 marks)

1. Displacement in the direction of the force
2. time
3. mass
4. velocity

Correct answer: A — Displacement in the direction of the force

30. Which structure contains most of the genetic material in a typical animal cell? (1.00 marks)

1. Cytoplasm
2. Nucleus
3. Mitochondria
4. Nitrification

Correct answer: B — Nucleus

31. A white light passing through a prism splits into colors due to: (1.00 marks)

1. Reflection
2. Refraction
3. Dispersion
4. Diffraction

Correct answer: C — Dispersion

32. Which vision problem is corrected using a concave lens? (1.00 marks)

1. Hyperopia
2. Myopia
3. Cataract
4. Colour blindness

Correct answer: B — Myopia

33. Among typical solids, liquids and gases, sound generally travels fastest in which state? (1.00 marks)

1. Solid
2. Liquid
3. Gas
4. Vacuum

Correct answer: A — Solid

34. Which formula is used to calculate power in an electrical circuit? (1.00 marks)

1. Voltage × Current
2. Current × Resistance
3. Voltage / Current
4. Resistance / Voltage

Correct answer: A — Voltage × Current

35. Which of the following materials is an insulator? (1.00 marks)

1. Copper
2. Aluminium
3. Rubber
4. Iron

Correct answer: C — Rubber

36. Identify the component that protects a circuit from overload. (1.00 marks)

1. Resistor
2. Capacitor
3. Fuse
4. Diode

Correct answer: C — Fuse

37. The flow of electric charge per unit time is called: (1.00 marks)

1. Voltage
2. Resistance
3. Electric current
4. Power

Correct answer: C — Electric current

38. Soap consists mainly of sodium or potassium salts of which type of substance? (1.00 marks)

1. Common salt
2. Baking soda
3. Fatty acids
4. Sugar

Correct answer: C — Fatty acids

39. Which type of galaxy has no definite shape? (1.00 marks)

1. Spiral galaxy
2. Elliptical galaxy
3. Irregular galaxy
4. Lenticular galaxy

Correct answer: C — Irregular galaxy

40. The force that keeps planets in orbit around the Sun is due to: (1.00 marks)

1. Magnetic force
2. Gravitational force
3. Electric force
4. Frictional force

Correct answer: B — Gravitational force