7th Science - Term 1 Exam 2024 - Original Question Paper with Solutions | Tirupattur District
FIRST TERM - SUMMATIVE ASSESSMENT(SA) - 2024-25
Class: 7 | SCIENCE
Time Allowed: 2.00 Hours | Max. Marks: 60
I. Choose the correct answer. (10x1=10)
1. Light year is the unit of
Answer: a) Distance
2. An element which is always Lustrous, Malleable and Ductile is
Answer: b) Metal
3. Which one of the following is an example for a metal.
Answer: a) Iron
4. Oxygen, Hydrogen and Sulphur are examples for
Answer: b) Non-metals
5. The metal which is liquid at room temperature is
Answer: c) Mercury
6. The basic unit of Matter is
Answer: b) Atom
7. __________ is positively charged.
Answer: a) Proton
8. Vegetative Propagation by leaves takes place in
Answer: a) Bryophyllum
9. Reproductive part of a Plant is
Answer: d) Flower
10. Climbing roots are seen in
Answer: c) Both of them
II. Fill in the blanks: (10x1=10)
11. Eyes are considered as windows to the world.
12. Tuberculosis is caused by the Bacterium Mycobacterium tuberculosis.
13. The male Reproductive part of a Flower is Androecium / Stamen.
14. After Fertilization the ovules becomes seeds.
15. Breathing Roots are seen in mangrove plants.
16. The smaller particles found in the atom are called sub-atomic particles.
17. Graphite is the only Non-metal which conducts electricity.
18. The smallest particle of matter that can exist by itself is molecule.
19. There are 118 number of known elements.
20. The Rate of Change of velocity is acceleration.
III. Match the following: (5x1=5)
| Column A | Correct Match (Column B) |
|---|---|
| 21. Displacement | Metre |
| 22. Light travelling through vacuum | Uniform Velocity |
| 23. Speed of Ship | Knot |
| 24. Centre of gravity of geometrical shaped objects | Geometric centre |
| 25. Stability | Larger base area |
IV. Answer any Ten questions: (10x2=20)
26. What is One light year?
One light year is the distance travelled by light in vacuum in one year. (1 light year = 9.46 x 1012 km).
27. Define Astronomical Unit.
An Astronomical Unit (AU) is defined as the mean distance between the Earth and the Sun. (1 AU ≈ 149.6 million km).
28. Length of Scale : metre
Speed of Aeroplane : __________
Speed of Aeroplane : __________
Speed of Aeroplane : Knot (or km/h)
29. Define Molecule.
A molecule is the smallest particle of an element or a compound that can exist independently and shows all the properties of that substance.
30. Write the Chemical formula for the following elements.
a) Hydrogen: H₂
b) Nitrogen: N₂
c) Ozone: O₃
d) Sulphur: S₈
b) Nitrogen: N₂
c) Ozone: O₃
d) Sulphur: S₈
31. Name the Sub-atomic particles.
The sub-atomic particles are Protons, Neutrons, and Electrons.
32. What are the Characteristics of Proton?
- It is a positively charged particle.
- It is located inside the nucleus of an atom.
- Its mass is approximately 1.672 x 10⁻²⁷ kg.
33. What are the two important parts of a Flower.
The two important (essential) parts of a flower are the Androecium (male reproductive part) and the Gynoecium (female reproductive part).
34. Define - Pollination.
Pollination is the process of transferring pollen grains from the anther of a flower to the stigma of the same or another flower.
35. What is Hygiene?
Hygiene is a set of practices performed to preserve health and prevent the spread of diseases.
36. Give any two Communicable disease, Which spread in your locality during Monsoon.
Cholera and Dengue fever.
37. What first aid will you provide in the case of Bruises?
Apply an ice pack or a cold compress on the bruised area for 15-20 minutes to reduce swelling and pain.
V. Answer briefly: (Any 3) (3x5=15)
38. Write about any three Communicable diseases in detail.
1. Tuberculosis (TB): It is an infectious disease caused by the bacterium *Mycobacterium tuberculosis*. It spreads through the air from person to person. It mainly affects the lungs. Symptoms include persistent cough, fever, weight loss, and night sweats.
2. Cholera: It is caused by the bacterium *Vibrio cholerae*. It spreads through contaminated food and water. It leads to severe diarrhea and dehydration.
3. Common Cold: It is caused by viruses like Rhinovirus. It spreads through respiratory droplets from an infected person's cough or sneeze. Symptoms include runny nose, sore throat, and sneezing.
39. Write a brief account on Pollination.
Pollination is the transfer of pollen grains from the male part (anther) to the female part (stigma) of a flower. It is essential for fertilization and the production of seeds and fruits.
- Types of Pollination:
- Self-pollination: Transfer of pollen to the stigma of the same flower or another flower on the same plant.
- Cross-pollination: Transfer of pollen from one flower to the stigma of a flower on a different plant of the same species.
- Agents of Pollination: Pollination is carried out by agents like wind, water, insects, birds, and animals.
40. Draw the Structure of an Atom and Explain the position of the sub-atomic particles.
[Note: A diagram should be drawn showing a central nucleus containing protons and neutrons, with electrons revolving around it in specific orbits or shells.]
Explanation:
- Nucleus: It is the dense, central core of an atom. It contains protons and neutrons.
- Protons (p+): These are positively charged particles located inside the nucleus.
- Neutrons (n): These are neutral particles (no charge) also located inside the nucleus.
- Electrons (e-): These are negatively charged particles that revolve around the nucleus in fixed paths called orbits or energy shells.
41. Differentiate Metals and Non-Metals.
| Feature | Metals | Non-Metals |
|---|---|---|
| State | Mostly solid (except Mercury). | Exist as solids, liquids, or gases. |
| Lustre | Have a shiny surface. | Are dull (except Iodine, Graphite). |
| Malleability | Can be beaten into thin sheets. | Are brittle (break easily). |
| Ductility | Can be drawn into wires. | Are not ductile. |
| Conductivity | Good conductors of heat and electricity. | Poor conductors (except Graphite). |
42. Write about the experiment to find the Centre of Gravity of the irregularly shaped plate.
Aim: To find the centre of gravity of an irregularly shaped lamina.
Apparatus: Irregular lamina, retort stand, plumb line, pin.
Procedure:
- Make three holes (A, B, C) near the edge of the lamina.
- Suspend the lamina freely from hole A using the pin on the stand.
- Hang the plumb line from the same pin and allow it to come to rest.
- Draw a line on the lamina along the plumb line's thread.
- Repeat the process by suspending the lamina from holes B and C, drawing lines each time.
Conclusion: The point where the three lines intersect is the Centre of Gravity (G) of the irregularly shaped lamina.