7th Science - First Term Summative Assessment 2024 - Solved Paper
Examination: First Term Summative Assessment Examination - 2024
Standard: 7th Std
Subject: Science
Time: 2.00 Hrs
Marks: 60
Part I: Choose the correct answer (10 x 1 = 10)
1. SI unit of density is
2. Light year is the unit of
3. Suppose the boy is enjoying a ride on a merry go round which is moving with a constant speed of 10 m/s. It is implies that boy is
4. Which one of the following is an example for a metal?
5. The metal which is liquid at room temperature is
6. ....................... is the positively charged.
7. The atomic number of an atom is the .......................
8. Reproductive parts of a plant is
9. Climbing roots are seen in
10. Our living place should be
Part II: Answer any 15 questions (15 x 2 = 30)
11. Fill in the blanks.
a) One astronomical unit is equal to ....................
b) The area of a leaf can be measured using a ....................
12. Arrange the following in correct sequence.
a) 1L, 100CC, 10L, 10CC.
b) Copper, Alluminium, Gold, Iron.
13. Analogy :
a) Area : m² :: Volume :
b) Water : kerosene :: ....................... : Aluminium.
14. Match the following.
- a) Displacement - Metre
- b) Light travelling through vacuum - Uniform velocity
- c) Speed of ship - Knots
- d) Stability - Larger base area
15. Distinguish between speed and velocity.
| Speed | Velocity |
|---|---|
| It is the rate of change of distance. | It is the rate of change of displacement. |
| It is a scalar quantity (has only magnitude). | It is a vector quantity (has both magnitude and direction). |
| Speed = Distance / Time | Velocity = Displacement / Time |
16. True / False.
a) NaCl represents one molecule of sodium chloride.
b) Argon is mono atomic gas.
17. What are compounds? Give two examples.
A compound is a pure substance consisting of two or more elements chemically combined in a fixed proportion by mass.
Examples: Water (H₂O), Carbon dioxide (CO₂).
18. Write the chemical formula for the following elements.
- a) Hydrogen - H₂
- b) Nitrogen - N₂
- c) Ozone - O₃
- d) Sulphur - S₈
19. What are isotones? Give one example.
Isotones are atoms of different elements which have the same number of neutrons in their nuclei.
Example: Carbon-13 (6 protons, 7 neutrons) and Nitrogen-14 (7 protons, 7 neutrons) are isotones.
20. What is atomic number?
21. Write two types of reproduction in plants.
- Asexual reproduction
- Sexual reproduction
22. What are the agents of pollination?
23. What is cross pollination?
24. What are thorns?
25. Analogy :
a) Typhoid : Bacteria :: Hepatitis : .......................
b) Tuberculosis : Air :: Cholera : .......................
26. What is Hygiene?
27. How to keep your hair clean and healthy?
- Wash your hair regularly with a mild shampoo.
- Rinse it well with clean water.
- Keep your comb clean and avoid sharing it.
- Eat a balanced diet rich in vitamins and minerals.
28. Give any two communicable diseases, which spread in your locality during monsoon.
- Cholera (spreads through contaminated water)
- Dengue Fever (spreads through mosquito bites)
29. What is Raster Graphics?
30. Match the following.
- a) Animations - 3D
- b) Raster - Pixles
- c) vector - Illustrator
- d) Virtual Reality - Visual communication
- e) Video story - Microsoft photostory
Part III: Answer any four questions (4 x 5 = 20)
31. Describe the graphical method to find the area of an irregularly shaped plane figure.
To find the area of an irregularly shaped figure using a graph sheet, follow these steps:
- Take a graph sheet with squares of known area (e.g., 1 cm²).
- Place the irregular object (like a leaf) on the graph sheet and trace its outline with a sharp pencil.
- Remove the object. You will see the outline on the graph sheet.
- Count the number of complete squares enclosed by the outline. Let this be 'M'.
- Count the number of incomplete squares. Out of these, count the squares that are more than half-covered. Let this be 'N'.
- Count the number of squares that are exactly half-covered. Let this be 'P'.
- Ignore the squares that are less than half-covered.
- The approximate area (A) of the figure can be calculated using the formula:
- Area (A) = M + N + (P/2) square units.
32. Explain the types of stability with suitable examples.
Stability is the ability of an object to maintain its position. There are three types of stability (or equilibrium):
- 1. Stable Equilibrium: An object is in stable equilibrium if it returns to its original position after being slightly displaced. This occurs when the center of gravity is as low as possible.
Example: A cone resting on its broad base. - 2. Unstable Equilibrium: An object is in unstable equilibrium if it does not return to its original position and topples over when slightly displaced. This occurs when the center of gravity is at its highest point.
Example: A cone balanced on its tip (vertex). - 3. Neutral Equilibrium: An object is in neutral equilibrium if it stays in the new position to which it has been displaced. The height of its center of gravity remains constant.
Example: A cone lying on its side.
33. List out the metals, non metals and metalloids which you use in your house, schools, compare their properties.
| Category | Examples in Use | Properties |
|---|---|---|
| Metals | Iron (gates, grills), Aluminium (utensils), Copper (electrical wires), Gold (jewelry). | Generally hard, lustrous (shiny), malleable, ductile, and good conductors of heat and electricity. |
| Non-metals | Carbon (as graphite in pencils), Oxygen (for breathing), Chlorine (in water purifiers), Sulphur (in matches). | Generally soft, non-lustrous (dull), brittle, and poor conductors of heat and electricity. |
| Metalloids | Silicon (in computer chips, smartphones), Boron (in cleaning agents). | Have properties intermediate between those of metals and non-metals. They are often semi-conductors. |
34. Draw the structure of an atom and explain the position of the sub-atomic particles.
Structure of an Atom:
An atom is composed of three fundamental sub-atomic particles: protons, neutrons, and electrons.
- Protons: These are positively charged particles located in the central part of the atom, called the nucleus.
- Neutrons: These are neutral particles (no charge) also located within the nucleus along with protons.
- Electrons: These are negatively charged particles that revolve around the nucleus in fixed, circular paths called orbits or shells.
35. Write a brief account on pollination.
Pollination is the process of transferring pollen grains from the male part of a flower (anther) to the female part (stigma).
Types of Pollination:
- 1. Self-Pollination (Autogamy): The transfer of pollen grains from the anther to the stigma of the same flower or another flower on the same plant. Example: Pea plant.
- 2. Cross-Pollination (Allogamy): The transfer of pollen grains from the anther of a flower on one plant to the stigma of a flower on another plant of the same species. Example: Apples, Sunflowers.
Agents of Pollination:
Pollination is facilitated by various agents, which can be biotic (living) or abiotic (non-living). These include:
- Wind (Anemophily): e.g., Maize, Grass.
- Water (Hydrophily): e.g., Vallisneria.
- Insects (Entomophily): e.g., Sunflower, Rose.
- Birds (Ornithophily): e.g., Hibiscus.
36. Write about any three communicable diseases in detail.
Communicable diseases are illnesses that can be transmitted from one person to another. Here are three examples:
-
Tuberculosis (TB):
- Causative Agent: Bacterium called Mycobacterium tuberculosis.
- Mode of Transmission: It spreads through the air when an infected person coughs, sneezes, or talks, releasing tiny droplets containing the bacteria.
- Symptoms: Persistent cough (sometimes with blood), chest pain, fever, night sweats, weight loss, and fatigue.
- Prevention: BCG vaccination, avoiding close contact with infected individuals, and maintaining good hygiene.
-
Cholera:
- Causative Agent: Bacterium called Vibrio cholerae.
- Mode of Transmission: It is primarily a water-borne disease, spreading through consumption of contaminated food or water.
- Symptoms: Severe watery diarrhea (often called "rice-water stool"), vomiting, muscle cramps, and rapid dehydration which can be fatal if untreated.
- Prevention: Drinking safe and clean water, proper sanitation, washing hands, and eating properly cooked food.
-
Common Cold:
- Causative Agent: Various viruses, most commonly the Rhinovirus.
- Mode of Transmission: Spreads through airborne droplets from coughing or sneezing, or by touching contaminated surfaces and then touching the face.
- Symptoms: Runny or stuffy nose, sore throat, cough, sneezing, and mild body aches.
- Prevention: Frequent hand washing, avoiding touching the face, and maintaining a healthy immune system.