To reduce exam fear, Class 7 Basic Science Question Paper Kerala Syllabus Set 4 provide good practice.
Kerala Syllabus 7th Standard Basic Science Model Question Paper Set 4
Time: 2¼ hour
Instructions:
- 15 minutes cool-off time is allotted for reading and understanding the activities.
- Answer any six questions.
Question 1.
a) Observe the picture.
Identify and write the incident ray and reflected ray.
Answer:
OA is the incident ray. OB is the reflected ray.
b) Classify the following based on the type of reflection:
- Smooth plane mirror
- Rough wall
- Still water
- Paper
- Polished metal
- Wooden surface
Answer:
| Regular Reflection | Irregular / Diffuse Reflection |
| Smooth plane mirror | Rough wall |
| Still water | Paper |
| Polished metal | Wooden surface |
c) Peculiarities of images formed by a plane mirror are given below. Select the correct ones.
1. Image is virtual.
2. Image is erect.
3. Image is magnified.
4. Image is of the same size as the object.
Options:
A. 1, 2 and 3 are correct
B. 2, 3 and 4 are correct
C. 1, 2 and 4 are correct
D. All are correct
Answer:
C. 1, 2 and 4 are correct
Question 2 has two parts 2 (A) and 2(B). WrIte any one 2(A) or 2(B) completely.
Question 2.
(A) Observe the picture
a) Vegetables in the fridge do not get damaged. But when the fridge is not working, vegetables start to decay. What is the reason?
A. Microorganisms die completely at low temperatures
B. Microorganisms remain inactive at low temperatures
C. Microorganisms multiply faster at low temperatures
D. Microorganisms do not exist in vegetables
Answer:
B. Microorganisms remain inactive at low temperatures
b) Food is kept in refrigerators to prevent decay. Write any two scientific reasons to justify this.
Answer:
At very low temperatures, the activity of microorganisms is slowed down or becomes inactive. This prevents food from decaying and keeps it fresh for a longer time.
c) Write a few suitable methods of food preservation.
Answer:
Putting food in a salt solution or sugar solution
- Drying food items
- Vinegar is also used as a food preservative
OR
(B) a) Examine the table given below and rewrite the mistakes, if any.
| Organ | Function |
| Small intestine | Absorbs a major part of water |
| Large intestine | Digestion is completed |
| Stomach | Absorption of digested food |
| Oesophagus | Digestion of food |
Answer:
| Organ | Function |
| Small intestine | Digestion is completed, and absorption of digested food |
| Large intestine | Absorbs a major part of water |
| Stomach | Partial digestion of food |
| Oesophagus | Passage of food from the mouth to the stomach (no digestion) |
b) Digestion is said to be completed in the small intestine. Do you agree with this statement? Write your response.
Answer:
Yes, I agree. The small intestine is the part of the digestive system where digestion is completed with the help of enzymes and bile. It also absorbs nutrients into the blood.
c) Which among the following is correct in the stages of nutrition?
Options:
A. Ingestion → Digestion → Absorption → Assimilation → Egestion
B. Absorption → Digestion → Ingestion → Absorption → Assimilation
C. Absorption → Ingestion → Absorption → Assimilation → Digestion
D. Absorption → Digestion → Assimilation → Ingestion → Egestion
Answer:
A. Ingestion → Digestion → Absorption → Assimilation → Egestion
Question 3.
a) You may have observed that while cooking on a gas stove, heat is transferred to the vessel and then to the food inside it.
a) Explain the different types of heat transfer that occur during this process.
Answer:
There are three types of heat transfer involved in cooking on a gas stove:
- Conduction: Heat is transferred from the flame to the metal pan through direct contact. The metal pan conducts heat to the food inside.
- Convection: Inside the pan, heat is transferred through the movement of hot liquids or gases (e.g., boiling water circulates due to convection currents).
- Radiation: Heat is also transferred directly from the flame to the pan in the form of infrared radiation.
b) Cooking vessels often have handles made of materials like plastic or wood. Give a reason for using such materials for handles.
Answer:
Handles are made of materials like plastic or wood because they are poor conductors of heat (non-conductors).
This prevents the handles from getting too hot, making them safe to hold and preventing bums while cooking,
c) How is heat mainly transferred in liquids and gases?
a) Conduction
b) Radiation
c) Convection
d) Reflection
Answer:
c) Convection
Question 4.
a) Examine the given statement and reason and write down the correct one.
Statement: Gooseberry has a sour taste.
Reason: Contains ascorbic acid.
A) Statement is correct. Reason is not suitable for the statement.
B) Statement is correct. Reason is suitable for the statement.
C) Statement is wrong. Reason is not suitable for the statement.
D) Statement and the reason are wrong.
Answer:
A) Statement is correct. Reason is not suitable for the statement.
b) Soap is made by using caustic soda, coconut oil, water, sodium silicate, stone powder, colour and perfume. The stages of soap preparation are outlined below. Complete the missing ones.
Answer:
1) Dissolve caustic soda in water and allow it to cool.
2) Add coconut oil when it has cooled and stir it.
3) Add sodium silicate and continue stirring.
4) Add stone powder, colour, and perfume. Mix thoroughly.
5) Pour the mixture into moulds.
6) Remove from the mould after solidification.
c) Name two natural indicators and write their colour change in acid and alkali.
Answer:
| Natural Indicator | Colour in Acid | Colour in Alkali |
| a) Turmeric | Yellow | Reddish-brown |
| b) Red cabbage | Red/Pink | Greenish/Blue |
Question 5.
a) Examine the table and find out the correct group.
| Name of the organ | Function related to excretion |
| 1. Kidney | A. Breaks down toxins |
| 2. Skin | B.Removes carbon dioxide and water vapour |
| 3. Lungs | C. Sweat |
| 4. Liver | D.Removes urea, excess water, and salts in the form of urine |
A) 1-D, 2-C, 3-B, 4-A
B) 1-A, 2-C, 3-B, 4-D
C) 1-D, 2-B, 3-C, 4-A
D) 1-D, 2-C, 3-B, 4-A
Answer:
A) 1-D, 2-C, 3-B, 4-A
b) Prepare posters as part of the anti-drug awareness campaign and display them in your school?
Answer:
c) What difference is there in the amount of urea in the blood vessel that reaches the kidney and leaves the kidney?
Answer:
The blood vessel that reaches the kidney has urea in greater quantities, and the blood vessel that leaves the kidney has urea in lesser quantities.
d) Name the organs mentioned in the pictures and identify the organ that does not belong to the group.
Answer:
1 – Kidney, 2 – Skin, 3 – Lungs
The skin is an organ that does not belongs to the group because it is an external organ that covers the body.
Question 6 has two parts 6 (A) and 6 (B). Write any one 6 (A) or 6(B) completely.
Question 6.
A. Observe the news report.
A) a) Draw a circle to represent the Sun.
Draw a smaller circle to represent the Moon.
Position the Moon between the Sun and the Earth.
Draw the shadow cast by the Moon onto the Earth.
Label the Sun, Moon, Earth, and shadow in your drawing.
Answer:
b) Explain what happens during a solar eclipse based on your diagram.
Answer:
In a solar eclipse, the Moon passes between the Sun and the Earth. When this happens, the Moon blocks the Sun’s light, casting a shadow onto the Earth. The area of the Earth that is covered by the shadow experiences a solar eclipse.
c) What are the risks of looking directly at a solar eclipse? Describe at least two safe ways to observe a solar eclipse.
Answer:
Direct observation of a solar eclipse can be harmful to the eyes. This is because intense sunlight can damage the retina, a sensitive part of the eye. Therefore, it is essential to use proper filters or indirect methods to observe a solar eclipse.
Safe methods for observing a solar eclipse include :
- Using solar eclipse glasses: These special glasses have a special filter that blocks harmful ultraviolet and infrared rays while allowing visible light to pass through.
- Using a solar filter for telescopes or binoculars: A solar filter should be attached to the front of the telescope or binoculars to protect your eyes.
(B) Analyse the news report
a) What are the harmful effects that cause soil pollution?
Answer:
The natural condition of the soil is ruined.
- Its capacity for holding water is reduced.
- The poisons in the pollutants reach plants and animals.
- Through food, these poisons reach man.
b) Write any two scientific methods of waste management.
Answer:
Vermi composting
Production of biogas
c) Classify and tabulate the following household waste into biodegradable, non-biodegradable and hazardous waste.
| Food Wastes, Paper, Bulbs, Footwear, CFL Lamps, Paint containers, Mobile phone battery, Vegetable wastes, Cardboard packing, plastic bottles, Glass bottles |
Answer:
| Biodegradable | Non-biodegradable | Hazardous waste |
| Food Wastes | Bulbs | CFL Lamps |
| Paper | Footwear | Mobile Phone Battery |
| Cardboard packing | Glass bottles | Paint containers |
| Vegetable Wastes | Plastic bottles |