Get complete and accurate DAV Class 4 SST Chapter 6 Question Answer Waste Management solutions based on the DAV CMC textbook We and Our World. Master concepts of Biodegradable vs Non-biodegradable waste, composting, landfills, recycling benefits, the 4 Rs, and environmental preservation.
A. Tick (âś“) the correct option
1. Animal and plant waste can be converted into—
(a) Biogas
(b) LPG
(c) Natural gas
Answer: (a) Biogas
Reason: Organic animal dung and plant residues are digested anaerobically in a biogas plant to produce clean biogas fuel.
2. It is the duty of _________ to keep our surroundings clean and green.
(a) The Government
(b) Citizens
(c) Both
Answer: (c) Both
Reason: Both civic authorities (providing sanitation systems) and citizens (not littering and segregating waste) share the responsibility of keeping areas green and clean.
3. It is easy to recycle—
(a) Plastic
(b) Fruits and vegetable peels
(c) Both
Answer: (c) Both
Reason: Organic fruit/vegetable scraps can be naturally recycled into rich compost, while plastic items can be melted and remolded into new goods.
4. Construction waste can be used for—
(a) Filling ditches
(b) Building walls
(c) Making pots
Answer: (a) Filling ditches
Reason: Broken bricks, concrete pieces, and rubble from construction sites serve as sturdy fill material for low-lying ditches and road foundations.
B. Fill in the blanks
1. Human waste in open fields must be covered with soil in rural areas.
2. Recycling is beneficial for the environment.
3. Biodegradable waste can be used to make compost.
4. Waste disposal is important to keep our surroundings clean.
5. The four Rs to reduce waste are reduce, reuse, recycle and refuse.
C. Match the following
| Column A | Column B (Correct Match) |
|---|---|
| 1. Biodegradable waste | (b) can be converted into harmless substances |
| 2. Non-biodegradable waste | (a) cannot be easily converted into harmless substances |
| 3. All living beings | (d) produce waste |
| 4. Recycling will benefit | (c) animals & humans both |
D. Answer the following questions
Question 1: What is waste? Name three diseases caused by waste materials thrown in open areas.
Answer: Waste refers to unwanted, discarded, and unusable materials that are thrown away after use.
Three common infectious diseases caused by heaps of open rotting waste are:
1. Cholera
2. Typhoid
3. Malaria / Dengue (caused by mosquitoes breeding in water collected in waste items)
Question 2: Highlight two differences between biodegradable and non-biodegradable waste.
Answer: Below is a clear comparison:
| Feature | Biodegradable Waste | Non-Biodegradable Waste |
|---|---|---|
| Decomposition | Breaks down and decays naturally by microorganisms into simple harmless substances. | Does not decay or decompose naturally and remains in the environment for hundreds of years. |
| Examples | Fruit and vegetable peels, paper, leaves, leftover food, and animal dung. | Plastic bags, glass bottles, metal cans, and thermocol. |
| Environmental Impact | Safe for the soil; turns into natural nutrient-rich compost. | Chokes drains, pollutes soil and oceans, and harms wildlife. |
Question 3: What are the benefits of recycling?
Answer: Major advantages of recycling are:
1. Conserves Natural Resources: Recycling old paper saves thousands of trees, and recycling metal and glass conserves raw earth ores.
2. Reduces Pollution & Landfills: Less waste piles up in dumping yards and burning of toxic plastic is avoided.
3. Saves Energy: Manufacturing goods from recycled materials requires much less electric energy than making them from scratch.
Question 4: Mention any two methods of waste disposal. Which one is the best in your opinion? Give one reason.
Answer: Two common methods of waste disposal are:
1. Composting: Dumping organic biodegradable kitchen and garden waste into a pit to turn into nutrient manure.
2. Landfills: Disposing of non-recyclable solid garbage into deep excavated areas outside the city and covering it with earth.
Best Method: Composting is the best method because it is 100% natural, eco-friendly, produces chemical-free nutrient manure for crops, and causes zero soil or groundwater contamination.
Question 5: Suggest two ways of reusing waste materials from our homes, school and offices.
Answer: Two effective ways of reusing waste are:
1. Reusing Containers: Clean used plastic jars, tin boxes, and glass bottles to store pulses, pens, or use them as small flowerpots.
2. One-sided Blank Paper: Use old printed sheets with blank backs for rough math practice, taking notes, or making creative paper crafts before recycling.
E. Waste Management Crossword Puzzle
Crossword Puzzle Clues & Answers:
Across Clues:
1. To use something again: REUSE
3. To give away something to someone: DONATE
4. Something useless: WASTE
Down Clues:
2. Converting a useless article to a useful one: RECYCLE
5. A CLOTH bag can be used again.
6. A PLASTIC bucket can be recycled.
Value-Based Question
Value-Based Reflection (School Waste Management): Question: A.R. Rahman has become famous all over the world for his contribution to music. What would be your contribution if you are made an incharge of waste management in your school?
Answer: If I am made the incharge of waste management in my school, my contributions would be:
1. Two-Bin Rule: Ensure every classroom has two separate dustbins—Green for pencil shavings and fruit peels (biodegradable) and Blue for plastic wrappers and packaging (recyclable).
2. School Compost Pit: Set up an eco-friendly compost pit in the school garden to convert garden dried leaves and canteen vegetable scraps into natural fertilizer for school plants.
3. Anti-Plastic Drive: Lead student assemblies to encourage carrying reusable steel tiffin boxes and water bottles instead of disposable plastic packaging.
🎉 Chapter 6 Completed!
đź“‘ Complete Book Chapters (DAV Class 4 SST – We and Our World):