In-text Questions — Ozone and Waste Disposal — Our Environment

1. 13 marksNCERT Cl-10 Science, In-text Q after Activity 13.9

   What is ozone and how does it affect any ecosystem?

   Hint. Ozone plays two very different roles depending on where it is — this question is about its role high in the atmosphere.

   Step 1 — What ozone is. Ozone (O₃) is a molecule made of three oxygen atoms, formed when high-energy UV radiation splits some O₂ molecules into free oxygen atoms, which then combine with more O₂ to form O₃.

   Step 2 — What it does at the higher levels of the atmosphere. At these higher levels, ozone shields the Earth's surface from harmful ultraviolet (UV) radiation from the Sun.

   Step 3 — Why this matters for an ecosystem. This UV radiation is highly damaging to organisms — for example, it is known to cause skin cancer in human beings — so the ozone layer protects every ecosystem it covers by blocking this radiation before it reaches living organisms.

   ✦ Answer: Ozone (O₃) is a three-oxygen-atom molecule formed in the upper atmosphere; there, it shields ecosystems by absorbing the Sun's harmful UV radiation before it can damage living organisms.

   Where students slip. Describing ozone only as a pollutant — that's true of ground-level (tropospheric) ozone, but at the higher levels of the atmosphere this same molecule performs an essential protective function.

2. 22 marksNCERT Cl-10 Science, In-text Q after Activity 13.9

   How can you help in reducing the problem of waste disposal? Give any two methods.

   Hint. One method reduces how much non-biodegradable waste gets made; the other helps at the disposal end.

   Step 1 — Reduce waste generation. Use fewer non-biodegradable materials, such as single-use plastics, choosing reusable alternatives instead, since this reduces how much non-biodegradable waste is generated in the first place.

   Step 2 — Segregate at source. Separate household waste into biodegradable and non-biodegradable categories, so that biodegradable waste can be composted and non-biodegradable waste can be sent for proper recycling or disposal.

   ✦ Answer: Reduce the use of non-biodegradable materials like single-use plastics, and segregate waste at home into biodegradable and non-biodegradable categories so each can be treated appropriately.

   Where students slip. Suggesting only 'throw it away properly' — segregating waste at the source and reducing generation are the two concrete methods this question is asking for.

Solutions written by the tuition.in editorial team and checked against the NCERT Class 10 Science textbook, Reprint 2026-27 (jesc113.pdf) — three in-text question sets (7 questions total) plus one end-of-chapter Exercise (9 questions, not the 8/13 an older manifest claimed). The chapter's own core content (ecosystems, food chains/webs, trophic levels, the 10% energy rule, biological magnification, ozone depletion, biodegradable/non-biodegradable waste) is intact. A fabricated fifth trophic level and an unverified 'Lindeman (1942)' name-drop were removed from the chapter page; content on the Chipko Movement, forest/wildlife conservation and India's environmental laws — which belongs to 'Sustainable Management of Natural Resources', the old Chapter 16 dropped entirely from the current 13-chapter book — was moved to the appendix.. Questions are referenced from the NCERT textbook for identification.