To reduce exam fear, Class 7 Basic Science Question Paper Kerala Syllabus Set 5 provide good practice.
Kerala Syllabus 7th Standard Basic Science Model Question Paper Set 5
Time: 2¼ hour
Instructions:
- 15 minutes cool-off time is allotted for reading and understanding the activities.
- Answer any six questions.
Question 1.
Roy and his mother are making tea. He observes and lists down some of the things that happen when tea is made. Those are given in the table below.
a) Complete the table.
| (i) ______ | (ii) ______ | Radiation |
| Water boils | The pot heats up | (iii) ______ |
Answer:
i) Conduction
ii) Convection
iii) The heated air
b) Observe the picture of the thermoflask.
Write down how each of the parts marked in the picture help to prevent heat loss.
Answer:
i) The vacuum between double walls – As there is no air, heat loss by conduction is controlled
ii) Inner surface coated with silver salts – Heat loss by radiation is controlled.
c) Apart from the parts marked in the figure, what are the other arrangements in the thermoflask to prevent heat loss? Write any one.
Answer:
Glass vessel and lid – Heat transmission through conduction will be very less.
2. Question 2 has two parts 2(A) and 2(B). Write any one 2(A) or 2(B) completely.
Question 2.
(A) a) The following are the general properties of acids and bases. Find out the correct statements among them
A. Acids have a sour taste.
B. Bases turn blue litmus to red.
C. Bases react with oxides and hydroxides to form water and salts.
D. Acids react with carbonates to form Hydrogen.
1. B and D are correct
2. C and D are correct
3. A and C are correct
4. All are correct
Answer:
3. A and C are correct
b) Glass containers are suitable for storing pickles. What may be the reason?
Answer:
Glass containers are suitable for storing pickles because glass is non-reactive and does not react with the acids present in pickles.
c) Complete the table.
| Food item | Acid content |
| i) | Malic acid |
| Tamarind | ii) |
| iii) | Citric acid |
| Buttermilk | iv) |
Answer:
| Food item | Acid content |
| i) Apple | Malic acid |
| Tamarind | ii) Tartaric acid |
| iii) Lemon | Citric acid |
| Buttermilk | iv) Lactic acid |
OR
(B) a) Different methods of producing quality seeds/pl anting materials are given below. Complete the table.
| Method | Features | Plants that can be produced |
| (i) | Flowers of different colours in one plant | Rose |
| (ii) | Producing quality seeds through artificial pollination | Coconut |
| Grafting | (iii) | Mango tree |
Answer:
(i) Budding
(ii) Hybridization
(iii) It enables us to combine the most desirable characteristics of the two plants in their flowers and Suits
b) Examine the given statement and reason and write down the correct one.
Statement: Plants produced by layering possess the same qualities as the mother plant.
Reason: Layering is a method of vegetative propagation where a new plant is grown directly from a stem of the mother plant, carrying all of its genetic information.
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:
B. Statement is correct. Reason is suitable for the statement.
Question 3.
Raju while reading a comic book, saw a task to find the correct word.
a) How can he identify the correct word?
Answer:
By placing the word in front of a plane mirror. Lateral inversion helps to identify the correct word.
b) Which of the following shows the wrong representation of image of the letters that appear in mirror when placed in front of a plane mirror.
Answer:
(iii) is wrong
c) Writing in front of an ambulance is shown below. Why is it written so?
Answer:
In the front of the ambulance, the word “AMBULANCE” is written laterally inverted so that when another ‘ driver looks in their rearview mirror, the word will appear correctly and this lets the driver to give way for the ambulance.
Question 4.
You are provided with some of the objects that are given below.
| Pen, Football, Instrument box, Plate, Steel glass, Cricket ball, Smiley ball |
Light a torch against each of the objects. Observe the shape of the shadow formed on the wall,
a) Classify the given objects into two as given below.
Answer:
| Objects that form circular Shadow | Objects that do not form circular Shadow |
| Football | Pen |
| Cricket ball | Instrument box |
| Smiley ball | Plate |
| Steel glass |
b) Write the result that helped you to classify the objects.
Answer:
Only spherical objects always form circular shadows.
Question 5.
Observe the picture of a branch which is separated from its parent plant after sprouting roots.
a) Write the name of this method of producing new plantlet.
Answer:
Layering
b) Write down any two merits of plantiets produced through this method.
Answer:
Merits of layering:
- Most of the plants can be grown this way
- The plantlets have the qualities of the parent plant.
- Through layering, we can produce more saplings within a short period.
- Flowering and fruiting of such plants are faster than those in plants formed from the seeds.
c) The steps of producing new plantiets in this method are given below write them in the correct order.
a. Cover with a polythene sheet.
b. Cut the branch and plant it in the soil.
c. Peel 6ff the bark iii a circular shape:
d. Select a branch of the plant from which plantlet is to be produced.
e. Cover the peeled off part with slightly moistened mixture’ of coconut fibre and soil.
Answer:
d) Select a branch of the plant from which the plantlet is to be produced,
c) Peel off the bark in a circular shape.
e) Cover the peeled-off part with a slightly moistened mixture of coconut fibre and soil.
a) Cover with a polythene sheet.
b) Cut the branch and plant it in the soil.
6. Question 6 has two parts 6 (A) and 6 (B). Write any one 6 (A) or 6 (B) 6 completely.
Question 6.
(A) A child’s research project is on the topic ‘ Safe food’. It should include the steps to be taken while selecting food items.
A) What are the signs of fresh fish?
Answer:
Fresh fiSh has finn, fresh flesh, clear eyes, shiny gills, and no foul smell.
B) What are the signs of spoiled fish?
Answer:
Spoiled fish has depressed flesh on pressing, detachçcl meat, green or dull gills, sunken eyes, and bad odours.
C) What factors should be considered while selecting milk and milk products?
Answer:
Factors to consider include the date of packing and expiry, damage to the packaging, proper sealing, refrigeration, brand logo, discoloiiriition, quality of the source.
D) What are the details recorded on packets of food substances?
Answer:
- The sign indicating quality.
- The packing date and-expiry date.
- The proportions of ingredients indicate.
- The names of .manufacturers1 and the maximum retail price (MRP).
- The signs indicating the use of vegetarian- non-vegetarian substances,
OR
(B) A) When the half part of the moon on which sunlight falls is visible from the Earth, which among the following can be seen to us.
a) The day will be a Full Moon Day.
b) The day will have a Half Moon during sunset.
c) That day will be a New Moon Day (Amavasi)
d) A small crescent will be visible on that day.
Answer:
b) The day will have a Half Moon during sunset.
B) Write the reasons for waxing and waning of the Moon.
Answer:
Waxing and waning (Vridhikshayam) is the difference in viewing the illuminated and shadow portions of the Moon as it revolves around the Earth.
C) Only one side of the Moon is seen facing the Earth. Why?
Answer:
Because revolution and rotation occur simultaneously.