To reduce exam fear, Class 7 Basic Science Question Paper Kerala Syllabus Set 2 provide good practice.
Kerala Syllabus 7th Standard Basic Science Model Question Paper Set 2
Time: 2¼ hour
Instructions:
- 15 minutes cool-off time is allotted for reading and understanding the activities.
- Answer any six questions.
Question 1.
a) A metal frame can be fixed to the wheel of the bullock cart. Explain how thermal expansion of objects is useful in this situation.
Answer:
The metal frame expands while heating. So it slips easily onto the wheel. As the frame cools, it contracts to the original size and fits tightly on the wheel.
b) Write any other two instances in which the thermal expansion of objects is useful.
Answer:
- To loosen the cap of a fountain pen that is tightened if it is heated.
- To take out a glass tumbler that got jammed into another, it is dipped in hot water.
c) Choose the correct statement from those given below, which is related to sea breeze and land breeze
A) Land gets heated sooner during the daytime.
B) The sea gets heated sooner during the daytime.
C) During the daytime, the air above the land gets heated and rises.
D) During the night land cools down sooner.
1. A and B are correct
2. A and D are correct
3. C and D are correct
4. All are correct
Answer:
2. A and D are correct
Question 2.
a) Given are some statements on the Human excretory system. Find out the correct statements from the following.
A) The primary function of the kidneys is to remove excess waste and fluid from the blood to produce urine, but they also have roles in regulating blood pressure and red blood cell production.
B) The main components of sweat are water and urea, which are the two primary waste products expelled by the skin.
C) The liver and lungs are also considered accessory excretory organs because they both play a role in eliminating waste products from the body.
1. A and C are correct.
2. B and C are correct.
3. Only A is correct.
4. Only C is correct.
Answer:
4. Only C is correct.
b) What are the functions of the skin as an excretory organ?
Answer:
The skin plays an excretory role by producing sweat through sweat glands. Sweat is a mixture of excess water and salts that are eliminated from the body. This process also helps in regulating body temperature.
c) What is the primary function of the renal artery and renal vein in relation to the kidneys?
Answer:
The renal artery carries blood containing waste products (like urea) and other substances to the kidneys for filtration, while the renal vein carries the filtered, cleaner blood away from the kidneys.
3. Question 3 has two parts 3(A) and 3(B). Write any one 3(A) or 3(B) completely.
Question 3.
(A) Observe the Sun, the Earth and the Moon in the given illustration.
a) What do pictures 1 & 5 indicate?
A. New moon day, Full moon day
B. Full moon day, New moon day
C. Waxing, Waning
D. Waning, Waxing
Answer:
A. New moon day, Full moon day
b) Write the reason for seeing them like this.
Answer:
When the moon comes to position 1, The lighted part of the moon is not facing the Earth, so the moon is not visible.
When the Moon is in position 5, the whole of the lighted part of the Moon is facing the Earth.
c) Waxing and waning happen on the moon. Why?
Answer:
From the new moon day to the full moon day, the lighted portion of the moon becomes more visible. This is called waxing. From the full moon day to the new moon day, there is a decrease in the visibility of the lighted area of the moon from the Earth. This is called waning. The difference in the visibility of the lighted and dark areas of the moon when observed from the Earth is the reason for the waxing and waning of the moon.
OR
(B) Examine the given table indicating the peculiarities of the two varieties of plants.
| Variety I | Variety 2 |
| Low yield | High yield |
| Active growth in our soil | Poor growth in our soil |
| Long life span | Short life span |
| Need less nurturing | Need more nurturing |
a) Which variety can be selected as stock and which one as scion to produce good saplings with high yield?
Answer:
Rootstock – Variety 1, Scion – Variety 2.
b) What are the methods adopted to produce good saplings with high yields? Explain anyone.
Answer:
Hybridisation, Crop rotation, Intercropping.
Hybridization: Hybridization is the method of production of seeds by artificially pollinating two plants which have different qualities and belong to the same species. From the seeds thus produced, those with superior quality are collected. These are the hybrid seeds.
c) Group the following varieties of seeds suitably.
| Annapooma, Bhagyalakshmi, Anugraha, Anamika, Jwalamukhi, Kiran, Lola, Hraswa |
Answer:
| Plants | Hybrid seeds |
| Paddy | Annapooma, Hraswa |
| Pea | Bhagyalakshmi |
| Chilli | Jwalamukhi, Anugraha |
| Lady’s finger | Kiran, Anamika |
| Cow pea | Lola |
Question 4.
“Due to 30% shortage of rainfall, Kerala will be in darkness. If monsoon is not received in full, we will be facing severe power crisis. This can be overcome to some extent by using electricity judiciously and avoiding its wastage.”
Have you noticed the news report?
A) Write down two precautions to avoid the wastage of electricity.
Answer:
Turn off lights and appliances when not in use: Ensure that you switch off lights, fans, and other electrical devices when leaving a room.
Use energy-efficient appliances: Opt for appliances that consume less electricity, such as LED bulbs and energy-efficient refrigerators.
B) What first aid will be given to a person affected with electric shock?
Answer:
The first step is to disconnect the electrical contact. You can switch off or remove the fuse for this. If it is not possible, , separate the person from the electric circuit using a dry wooden stick or another suitable insulator.
In the case of heart failure, perform chest compressions. Place one hand on top of the other and apply continuous pressure on the victim’s chest. This should be done until the heart starts beating again.
If breathing stops, give artificial respiration. Keep the body warm by massaging.
Question 5.
a) Is there any relation between the distance to the object and the distance to the image from a plane mirror? Design an experiment to prove this relation.
Answer:
The distance to the object and the distance to the image from a plane mirror are the same. Fix a plane
mirror vertically on a table using double-sided tape. Place a lighted candle at a certain distance from the plane mirror (say, 3 cm). Repeat the experiment by placing the candle at different positions (say, 4 cm, 5cm, etc.,). Observe the position of the image in the mirror. We can observe that the distance from the object to the image in a plane mirror is equal to the distance from the object to the mirror
b) Write two peculiarities of the image formed in a plane mirror.
Answer:
Virtual and erect
The size of the object and the image is the same.
Question 6 has two parts 6 (A) and 6 (B). Write any one 6 (A) or 6 (B) completely.
Question 6.
(A) A) The observation result of an experiment is given below. Identify the gases formed
| Acids | Substance | Gas |
| Vinegar | Zinc piece | i) |
| Vinegar | Baking soda | ii) |
Answer:
i) Hydrogen
ii) Carbon dioxide
B) Write the methods to identify the gases produced in this chemical reaction.
Answer:
i) Collect a small sample of the gas in a test tube and bring a lit match or splint near the mouth of the test tube. If the gas is hydrogen, then it will bum with a pop sound,
ii) Bubble the gas through limewater. If the gas is carbon dioxide, the limewater will turn milky.
C) Name any two acids used in the laboratory instead of vinegar.
Answer:
Hydrochloric Acid, Sulphuric Acid
(B) Listen to the words of the earthworm.
A. How does the overuse of chemical pesticides and chemical fertilisers affect the soil, men, and other living things?
Answer:
Fertilisers boost crop yields, but their excessive usage has hardened the soil, reduced fertility, strengthened insecticides, polluted air and water, and emitted greenhouse gases, creating health and environmental risks.
B. Write the method of preparation of a bio-pesticide.
Answer:
Tobacco Decoction: Chop 100 grams of tobacco and soak it in one and a half litres of water for a day. Squeeze it and filter it. Dissolve 10 grams of washing soap in it. Dilute it by adding twice the quantity of water and spray it on plants.
C. Name any two bio-fertilisers.
Answer:
Cow dung, Compost.