6th Class Science Second Mid Term Test 2024 - Solved Question Paper
I. Choose the correct answer. (5x1=5)
1. ---------- is a Good conductor.
2. An iron ball at 60°C is dropped in mug containing water at 60°C. The heat will ----------.
3. Formation of curd from milk is ----------.
4. The control centre of the eukaryotic cell is ----------.
5. Which one of the following is not an unicellular organism?
II. Match the Following. (5x1=5)
| Question | Correct Match |
|---|---|
| 6. Heat | Joule |
| 7. Temperature | Kelvin |
| 8. Thermal Equilibrium | No heat flow |
| 9. Ice Cube | 0°C |
| 10. Boiling Water | 100 °C |
III. Answer any five of the following questions. (5x2=10)
11. What do you understand by thermal equilibrium?
12. i) Burning of match stick : ---------- change
Rotation of the Earth : ---------- change.
Rotation of the Earth : Periodic change.
12. ii) Give one example for each case that happens around you.
a) Physical change b) Chemical change
b) Chemical change: Rusting of an iron nail.
13. What are the organelles found only in Plant cell?
14. i) Food Producer : Chloroplast :: Power house : ----------
14. ii) Spirogyra : Plant cell :: Amoeba : ----------
15. Give any three examples of eukaryotic cell.
16. What is a solution?
17. Define temperature.
IV. Answer in detail. (2x5=10)
18. a) Explain thermal expansion with suitable examples.
The increase in the volume of a substance due to heating is called thermal expansion. Most substances expand when heated and contract when cooled. Expansion occurs in solids, liquids, and gases.
- Expansion in Solids: When solids are heated, the particles vibrate more vigorously and move farther apart, causing the solid to expand.
Example: Gaps are left between railway tracks to allow for expansion during the hot summer months. Without these gaps, the tracks would bend. - Expansion in Liquids: Liquids generally expand more than solids when heated.
Example: In a thermometer, the mercury or alcohol inside expands when it comes in contact with a hot object, causing the level to rise and indicate the temperature. - Expansion in Gases: Gases expand the most when heated.
Example: If a balloon is left in the hot sun, the air inside it gets heated, expands, and causes the balloon to inflate further or even burst.
(OR)
18. b) Give one Example for each case.
i) Slow and Fast changes
- Slow change: The rusting of iron.
- Fast change: The bursting of a firecracker.
ii) Reversible and Irreversible change
- Reversible change: Melting of ice to form water.
- Irreversible change: Burning of paper to form ash.
iii) Desirable and Undesirable change.
- Desirable change: Ripening of fruits.
- Undesirable change: Spoiling of food.
19. a) Tabulate any five cell organelles and their function.
| Cell Organelle | Function |
|---|---|
| Nucleus | Controls all the activities of the cell. It is also called the "brain" of the cell. |
| Mitochondria | Generates energy for the cell in the form of ATP. It is known as the "powerhouse" of the cell. |
| Cell Wall | (In plant cells) Provides rigid structural support and protection to the cell. |
| Chloroplast | (In plant cells) Contains chlorophyll and is the site of photosynthesis. |
| Vacuole | Stores water, food, and waste products. It is large in plant cells and small in animal cells. |
(OR)
19. b) Draw a neat labelled diagram of a Plant cell.
A labelled diagram of a Plant cell.
Key parts to label in a plant cell diagram:
- Cell Wall
- Cell Membrane
- Cytoplasm
- Nucleus
- Chloroplast
- Large Central Vacuole
- Mitochondrion
- Endoplasmic Reticulum
- Golgi Apparatus