| 1. | radioactive wastes |
| 2. | genetically modified hazardous microbes |
| 3. | methyl isocyanate gas |
| 4. | chlorofluorocarbons |
| Assertion(A): | Discharge of sewage into rivers can cause mortality of fish and other aquatic creatures downstream from the point of sewage discharge. |
| Reason (R): | Micro-organisms involved in the biodegradation of organic matter in the receiving water body consume a lot of oxygen, and as a result, there is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. |
| 1. | Both (A) and (R) are True and (R) correctly explains the (A). |
| 2. | (A) is True but (R) is False. |
| 3. | (A) is False but (R) is True. |
| 4. | Both (A) and (R) are True but (R) does not correctly explain the (A). |
| Assertion (A): | A high dose of UV-B causes inflammation of cornea, called snow-blindness. |
| Reason (R): | UV radiation of wavelengths shorter than UV-B are almost completely absorbed by Earth’s atmosphere, given that the ozone layer is intact. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A) |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | Both (A) and (R) are False. |
| Statement I: | Irrigation without proper drainage of water leads to water-logging in the soil. |
| Statement II: | Besides affecting the crops, water-logging draws salt to the surface of the soil. |
| 1. | Statement I is incorrect; Statement II is correct |
| 2. | Statement I is correct; Statement II is correct |
| 3. | Statement I is correct; Statement II is incorrect |
| 4. | Statement I is incorrect; Statement II is incorrect |
| Assertion (A): | Primary contaminants for accelerated eutrophication of lakes are nitrates and phosphates. |
| Reason (R): | Nitrates and phosphates are plant nutrients which over-stimulate the growth of algae. |
| 1. | Both (A) and (R) are True and (R) correctly explains the (A). |
| 2. | Both (A) and (R) are True but (R) does not correctly explain the (A). |
| 3. | (A) is False but (R) is True. |
| 4. | (A) is True but (R) is False. |
Consider the given two statements:
| Assertion (A): | Recycling, an essential element of e-waste management, must be carried out properly especially in developing countries. |
| Reason (R): | Informally recycling – much of it by hand in developing countries, exposes workers to hazardous and carcinogenic substances such as mercury, lead and cadmium. |
| 1. | (A) is true (R) but is False |
| 2. | Both (A) and (R) are True and (R) correctly explains (A) |
| 3. | Both (A) and (R) are True and but (R) does not correctly explain (A) |
| 4. | Both (A) and (R) are False |
| 1. | Kilobase | 2. | Dobson unit |
| 3. | Decibels | 4. | Decameter |