CBSE 7th Standard Science Wastewater Story Important Questions And Answers Study Material - QB365 Set A | QB365

7th Standard CBSE Syllabus & Materials

7th Standard CBSE

CBSE 7th Standard Science Wastewater Story Sample Question Papers Study Material - QB365

NEW

7th Standard CBSE

CBSE 7th Standard Science Forests: Our Lifeline Sample Question Papers Study Material - QB365

NEW

7th Standard CBSE

CBSE 7th Standard Science Water: A Precious Resource Sample Question Papers Study Material - QB365

NEW

7th Standard CBSE

CBSE 7th Standard Science Light Sample Question Papers Study Material - QB365

NEW

7th Standard CBSE

CBSE 7th Standard Science Electric Current and Effects Sample Question Papers Study Material - QB365 Set C

NEW

7th Standard CBSE

CBSE 7th Standard Science Electric Current and Effects Sample Question Papers Study Material - QB365 Set B

CBSE 7th Standard Science Wastewater Story Important Questions And Answers Study Material - QB365 Set A

Published on: 31/10/2025

Question Set A

CBSE 7th Standard Science Wastewater Story Important Questions And Answers Study Material - QB365

Download CBSE Class 7th Standard CBSE Science question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 7th Standard CBSE Science

Questions + Answers key

Take MCQ Science Test

QB365 Student Learing Managemnet System

Std: 7th Standard CBSE - Science

chapter: Wastewater Story - Important Questions And Answers

Visit QB365-SLMS - https://www.qb365.in/slms/ Complete Questions and Answers

Questions:

Amarbel is an example of

(a)

autotroph

(b)

parasite

(c)

saprotroph

(d)

host

Products of a neutralisation reaction are always

(a)

an acid and a base

(b)

an acid and a salt

(c)

a salt and water

(d)

a salt and a base

The arboreal animal among the following is

(a)

elephant

(b)

lion

(c)

butterfly

(d)

lion-tailed macaque

If iodine is dropped on the boiled leaf it gives blue-black colour due to the presence of

(a)

starch

(b)

protein

(c)

fat

(d)

vitamin

Cud is the name given to the food of ruminants which is

(a)

swallowed and undigested

(b)

swallowed and partially digested

(c)

properly chewed and partially digested

(d)

properly chewed and completely digested

Name any four useful products other than wood, which we get from forests.

Mention the period proclaimed as the International Decade for action on Water for Life.

Unscramble the following terms related to modes of nutrition:
(i) RASPAEIT,(ii) ROPEHYSTAp, (iii) TOROPHAUT, (iv) SIBIOMSIS.

What type of substance is formed when a metal oxide is dissolved in water ? What are these generally called?

10.

Explain the mode of feeding of starfish.

11.

Why do we cover plug pin holes which are within the reach of children with cellotape or plastic cover when not in use?

12.

What is the importance of breathing.

13.

Write differences between decomposers and scavengers.

14.

The terms sewage, sewers and sewerage are interlinked with each other. Can you explain, how?

15.

Complete the table given below of the contaminant survey.

Types of sewage	Point of origin	Substances which contaminate	Any other remark
Sullage water	Kitchen
Foul waste	Toilets
Trade waste	Industrial and commercial organisations

16.

Vivek went to visit his grandfather in village where he saw that his grandfather's field of wheat is infected with fungus but no one is aware of this. Vivek told him that he should use an antifungal agent in his fields to stop this infection?
(a) What is fungus?
(b) Can fungus only cause disease or can it be helpful also?
(c) What values are shown by Vivek?

17.

How will you prove that light travels in straight line?

18.

What are chemical fertilizers? Write their harmful effects

19.

The bacteria Rhizobium lives in the roots of ...........

20.

Are the days shorter in winter than in summer?

21.

Does sweat serve any other function?

22.

Why is difficult of force the paper ball into the bottle?

23.

Can you say why your parents insist that you should eat regularly?

24.

Complete the paragraph related to the history of silk moth by filling in the blanks.
The_______(a)________silk moth lays_______(b)__________, from which hatch _______(c)_______called_______(d)_________or________(e)_______.They grow in size and when caterpillar is ready to enter the next stage of its life history called ________(f)_______, it first weaves a covering to hold itself, which is known as________(g)_________..

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

(b)
parasite

(d)
lion-tailed macaque

(a)
starch

(b)
swallowed and partially digested

Four useful products other than wood which we get from forests are gum, spices, fodder for animals and medicinal plants.

2005 -2015 is the period proclaimed as the International Decade for action on Water for Life.

(i) PARASITE, (ii) SAPROPHYTE, (iii) AUTOTROPH, (iv) SYMBIOSYS

When a metal oxide is dissolved in water, a base is formed e.g., sodium oxide (Na₂O) in water gives sodium hydroxide. These are called alkalies.

10.

Starfish feeds on aquatic animals which are covered by hard shells of calcium carbonate. After opening the shells, the starfish pops out its stomach through its mouth to eat the soft animals inside the shell. After eating the animal, the stomach goes back into the body and the food is slowly digested.

11.

The child may put his/her fingers into the socket and he/she may get an electric shock which could be fatal.

12.

All the organisms need energy for their various functions. Energy is released from the breakdown of food (glucose) with the help of oxygen. The breathing ensures the continuous supply of oxygen to different body cells.

13.

Difference between decomposers and scavengers is

Decomposer	Scavenger
These are the microbes which break dead organic matter into simple molecules to be used by plants again.	These animals eat the body of dead animals and are called cleaning agent of forests, e.g. jackal, fox, vultures, etc.

14.

The terms like sewage, sewers and sewerage are interlinked with each other because sewage is a mixture of wastewater coming out of homes and other places. Sewers are pipes which carry sewage and sewerage is a network of sewage carrying pipes.

15.

Given below is the table of contaminant survey explaining types of sewage with their point of origin and contaminate in them.

Types of sewage	Point of origin	Substances which contaminate	Any other remark
Sullage water	Kitchen	Cooking oils, fats, etc.	May choke drains
Foul waste	Toilets	Faeces and urine	Cause diseases like dysentery, cholera, etc
Trade waste	Industrial and commercial organisations	Chemicals like paints, solvents, motor oil, etc	Causes water and soil pollution

16.

(a) Fungus are non-green plants that grow on dead and decaying matter for their food.
(b) Fungus are also useful as it can cure different type of infections.
(c) Vivek is sincere, curious and knowledge with a keen sense of applying it where necessary.

17.

Take three cardboards of similar size and make a hole in the centre of each. Make sure that the size and position of the hole is the same in each cardboard.
Now put the three cardboards in vertical position with the help of bricks in such a way that the holes in the three cardboards are in a straight line. Place a lighted candle in front of the cardboard no. 1 as shown in Fig. Look through the hole of the last cardboard no. 3.

The flame can be seen clearly through the holes. When one of the cardboards is slightly raised, no flame can be seen. This shows that light travels in a straight line. No flame can be seen when the holes of the three cardboards are not in a straight line because light can not bend.

18.

The chemical substances which are rich in nutrients and used to maintain fertility are called fertilizers. They also produce harmful effects. They ramain in soil and spoil the porous structure of the soil which is essential for plant growth. They also kill the soil organisms like earthworms. Earthworms burrows and loosens the soil and makes it porous.

19.