Environmental Geography Questions and Answers

Answer: C

The answer is (A) is true but (R) is false.

Lindeman's ten per cent law (1942) states that only about 10 per cent of the energy at one trophic level is passed on to the next; the rest is used in respiration or lost as heat. The assertion is a fair statement of that rule.

The reason is false. Energy flow in a food chain is unidirectional: it passes from the Sun to producers, then to herbivores and carnivores, and is lost as heat at every step. It never flows back to a lower level. Nutrients cycle; energy does not.

Answer: A

The report is The Brundtland Report.

The World Commission on Environment and Development, chaired by Norwegian Prime Minister Gro Harlem Brundtland, published Our Common Future in 1987. It defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs, and the report is known by its chair's name.

The other titles are not the name of the Commission's report: the second and third are vague descriptions, and the 'Environmental Justice Report of 1987' borrows the right year to mislead.

Answer: D

The ascending order is (3), (4), (2), (1).

In the standard estimates of contribution to enhanced global warming, carbon dioxide contributes by far the most, about half or more; methane comes next; CFCs follow; and nitrous oxide contributes the least of the four. From smallest to largest: nitrous oxide, CFCs, methane, carbon dioxide.

Option A puts carbon dioxide first, which is close to the descending order, the reverse of what is asked. Options B and C place carbon dioxide in the middle of the list, which understates its dominant share.

Answer: B

The document is Agenda 21.

Agenda 21 was adopted at the UN Conference on Environment and Development (the Earth Summit) at Rio de Janeiro in 1992. It is a comprehensive, non-binding action plan for sustainable development in the twenty-first century, with chapters on financial resources, combating poverty, sustainable agriculture and rural development, combating deforestation and conserving biological diversity.

The Kyoto Protocol (1997) and the Paris Agreement (2015) deal only with climate change, and the Brundtland Commission produced the 1987 report Our Common Future, not this document.

Answer: C

The process is Calcification.

Where evapotranspiration exceeds precipitation, as in semi-arid grasslands, water does not pass right through the soil. Calcium carbonate and other bases are leached only a short way down and then accumulate in a lime-rich horizon, producing soils such as chernozems.

Podzolization occurs under cool humid climates and laterization under hot wet climates, both where precipitation exceeds evaporation and leaching is strong. Glaciation is a process of ice, not of soil formation.

Answer: D

The largest ecosystem on the earth is the Marine ecosystem.

The oceans cover about 71 percent of the earth's surface and, with their depth, hold by far the greatest volume of living space. They contain the largest single ecosystem, and marine plankton produce a large share of the world's oxygen.

Terrestrial ecosystems together cover only about 29 percent of the surface, grassland is one terrestrial biome within that, and anthropogenic ecosystems, such as farms and cities, are smaller still.

Answer: D

The correct matching is a-3, b-1, c-2, d-4.

• Herbivorous: the hippopotamus, which grazes on grass.
• Carnivorous: the penguin, which eats fish, squid and krill.
• Omnivorous: the rat, which eats almost anything.
• Decomposers: earthworms, which break down dead organic matter.

Option C makes the rat a decomposer and the earthworm an omnivore, and A and B make the penguin a herbivore or the rat a carnivore.

Answer: B

The key gives Only (b).

Synthetic fertilizers are applied to the surface and dissolve in soil water, so their nutrients act in the top soil, the root zone where most crop roots feed. That is statement (b), and the key treats (a), a middle layer, as wrong.

Statement (c) is false: chemical fertilizers add nutrients but no organic matter, so they do not raise the soil's water-holding capacity. It is manure, compost and other organic matter that improve soil structure and moisture retention. Every option including (c) is therefore wrong.

Answer: A

A plant and animal community covering a large area is a Biome.

A biome is a large natural community of plants and animals adapted to a particular climate, such as the tropical rain forest, the savanna, the desert or the tundra. It is the largest unit of community classification on land.

The biosphere is the whole zone of life on earth, much larger than any one community. Biodiversity is the variety of life, and ecology is the science that studies organisms and their environment, not a community itself.

Answer: A

The descending order is Forest - Open ocean - Grassland - Cultivated land.

Total net primary productivity is productivity per unit area multiplied by the area covered. Using the widely cited estimates of Whittaker and Likens, the world's forests together produce the most, roughly 70-80 billion tonnes of dry matter a year. The open ocean has low productivity per square metre but covers so vast an area that its total, about 40 billion tonnes, comes second. Grasslands and savannas come next, and cultivated land, with a much smaller area, is last.

The other orders confuse productivity per unit area with total productivity.