10th Science Important 2 Mark Questions with Answers

Maximize your efficiency and score quick marks in your upcoming board exams with our curated list of 10th Science Important 2 Marks questions. Short-answer questions are the backbone of the science question paper, testing your core conceptual clarity across Physics, Chemistry, and Biology. This comprehensive guide covers frequently repeated questions, vital definitions, scientific reasons, laws, and basic numerical problems from all chapters. Practicing these high-yielding questions will help you manage your time perfectly during the exam and secure maximum marks in the short-answer section.

X SCIENCE - TWO MARKS

Important 2 Marks Questions

1. Why does the sky appear blue in colour?

2. Write any two features of natural and artificial radioactivity?

3. Distinguish between reversible and irreversible chemical reactions.

4. Classify the following compounds based on the pattern of carbon chain and give their structural formula: (i) Propane (ii) Benzene

5. What is vascular bundle?

6. Why is circulation in man referred to as 'Double Circulation'?

7. Identify the disorder with which the person shown in the figure is suffering.

8. Why is Euploidy considered to be advantageous to both plants and animals?

9. What are the advantages of using biogas?

10. A lift is moving downwards with an acceleration of 1.8 m s^-2. What is apparent weight realised by a man of mass 50 kg?

11. Understand the assertion statement and the reason given and choose the correct choice.
Assertion: Gas is highly compressible than solid and liquid
Reason: Inter atomic or intermolecular distance in the gas is comparably high.
a) Both the assertion and the reason are true and the reason is the correct explanation of the assertion. b) Both the assertion and the reason are true but the reason is not the correct explanation of the assertion. c) Assertion is true but the reason is false d) Both the assertion and the reason are false.

12. Calculate the effective resistance of the given circuit across terminals AC.

13. Why does an empty vessel produce more sound than a filled one?

14. Analyse the given assertion and reason. Choose the correct choice.
Assertion (A): The nature of chemical bonding in HF molecule is ionic in nature.
Reason (R): The difference in electronegativity values between H and F is 1.9.
i) A and R are correct, R explains A. ii) A is correct, R is wrong.
iii) A is wrong, R is correct. iv) A and R are correct, R doesn't explain A

15. How does leech suck blood from the host?

16. Name the parts of the hind brain?

17. What is colostrum? How is milk production hormonally regulated?

18. Define Ethnobotany and write its importance.

19. What are psychotropic drugs?

20. Compound A is a colourless, crystalline, hydrated salt of magnesium. On heating it becomes an anhydrous salt. The number of water molecules lost by compound A is equal to number of water molecules present in green vitriol on heating.
i) Identify compound A
ii) Give the Chemical equation for this heating reaction.

21. Understand the assertion statement and the reason given and choose the correct choice.
Assertion: When a person swims he pushes the water using the hands backwards and the water pushes the person in the forward direction
Reason: For every action there is an equal and opposite reaction.
a) Both the assertion and the reason are true and the reason is the correct explanation of the assertion. b) Both the assertion and the reason are true but the reason is not the correct explanation of the assertion. c) Assertion is true but the reason is false. d) Both the assertion and the reason are false.

22. State Rayleigh's law of scattering.

23. Define: Relative atomic mass.

24. If the pH value of solution is zero then what will be the nature of the solution? Give reason.

25. What is photosynthesis and where does it occur in a cell?

26. What are the glands embedded in the Rabbit skin to regulate the body temperature?

27. Correct the following statements:
i) Sympathetic nervous system is a part of central nervous system.
ii) All the nerves in the body are covered and protected by meninges.

28. The degenerated wing of a kiwi can be considered as an acquired character. Give the reason.

29. Understand the assertion statement and the reason given and choose the correct choice.
Assertion: Colchicine reduces the chromosome number.
Reason: It promotes the movement of sister chromatids to the opposite poles.
a. Assertion is correct and reason is wrong b. Reason is correct and the assertion is wrong c. Both assertion and reason is correct d. Both assertion and reason is wrong

30. A piece of wire having a resistance of 5 ohm cut into five equal parts. If the five parts of the wire are connected in parallel, then find the effective resistance of the combination?

31. Why are traffic signals used in red colour?

32. State whether the following statement is true or false, justify your answer: During the process of transferring heat energy, the body at lower temperature is cooled while the body at higher temperature is heated.

33. A source producing a sound of frequency 90 Hz is approaching a stationary listener with a speed equal to (1/10) of the speed of sound. What will be the frequency heard by the listener?

34. Copper is a reddish brown metal, that reacts with O₂ at less than 1370 K to give A, a black coloured compound. At a temperature greater than 1370 K, Copper reacts with O₂ to give B which is a red coloured compound. Write the balanced chemical equations for the formation of A and B.

35. Why are the teeth of rabbit called heterodont?

36. What are the structures involved in the protection of brain?

37. Differentiate phenotype and genotype.

38. Mark the correct statement:
Assertion: rDNA is superior over hybridization techniques.
Reason: Desired genes are inserted without introducing the undesirable genes in target organisms.
a. Assertion is correct and reason is wrong b. Reason is correct and the assertion is wrong c. Both assertion and reason is correct d. Both assertion and reason is wrong

39. Write the importance of rainwater harvesting.

40. From the value of ionic product of water at 25°C, find out the concentration of hydroxyl ions. (At 25°C concentration of hydrogen ions in water is 10^-7 mol/dm³)

41. Complete the ray diagram of a concave lens.

42. A container of capacity 70 ml is filled with a liquid up to 50 ml. When it is heated the liquid level falls to 48.5 ml and then rises to 51.2 ml. Find the apparent and real expansion.

43. Match the following:

a. Fuel	- i) lead
b. Moderator	- ii) Helium
c. Coolant	- iii) heavy water
d. Shield	- iv) uranium

44. Calculate the pH value of 1 × 10^-4 M KOH solution.

45. How is diastema formed in rabbit?

46. Write the functions of cerebellum.

47. Write the characteristics of insect pollinated flowers.

48. What is meant by transgenic organisms?

49. How are e-wastes generated?

50.
i) 'X' is an element that belongs to 1st group of the modern periodic table. 'X' is a gas and its covalent radius value is 0.37 Å. Identify and write the chemical symbol of 'X'.
ii) A is a metal and belongs to Boron family in modern periodic table acts as a good reducing agent. It reduces iron oxide into iron. It is used to make household utensils. Write the balanced chemical equation for the reduction of iron oxide by 'A'.