World Natural Vegetation & Biomes – NDA Geography PYQs

NDA 2019-I

Q. 1. Which one of the following is the largest biome on Earth?

(a) Tropical Rainforest

(b) Taiga (Boreal Forest)

(c) Tundra

(d) Temperate Grassland

Answer: (b) Taiga (Boreal Forest)

Explanation: The Taiga (boreal forest) is the world’s largest terrestrial biome by area. It covers approximately 11–12 million km² across Canada, Alaska, Russia (Siberia), and Scandinavia: forming a vast belt around the Northern Hemisphere. Although the Tropical Rainforest is extremely biodiverse and extensive (~5.5 million km²), the taiga covers a larger total area. The tundra also covers a vast area, but the taiga is generally considered the largest single terrestrial biome. Concept Tested: Taiga (Boreal Forest): world’s largest terrestrial biome (~11-12 million km²); Northern Hemisphere belt

NDA 2018-II

Q. 2. Which of the following is the natural vegetation associated with the Mediterranean climate?

(a) Shrubs and scrublands with hard, leathery leaves

(b) Dense tropical forest

(c) Grassy plain with scattered trees

(d) Extensive coniferous forest

Answer: (a) Shrubs and scrublands with hard, leathery leaves

Explanation: Mediterranean climate vegetation is characterised by xerophytic (drought-adapted) shrubs and scrublands with hard, leathery, waxy leaves: adaptations to the long, hot, dry summer. Regional names: Chaparral: California, USA. Maquis (or Macchia): France, Italy, Corsica. Garrigue: lower, more open scrubland in South France. Fynbos: South Africa (Cape region). Mallee scrub: southwestern Australia. These plants have small leaves (or spines), thick bark (fire-adapted), and deep roots to access groundwater during the dry summer. Concept Tested: Mediterranean vegetation: hard, leathery-leafed shrubs (chaparral/maquis/garrigue); xerophytic drought adaptations

NDA 2017-I

Q. 3. Tundra vegetation is characterised by:

(a) Tall grasses and scattered trees

(b) Dense forest of broad-leaved trees

(c) Extensive coniferous forests

(d) Mosses, lichens and dwarf shrubs

Answer: (d) Mosses, lichens and dwarf shrubs

Explanation: Tundra vegetation is the characteristic plant life of the Arctic and sub-Arctic regions (and high mountain plateaus). It consists of: Mosses: the most abundant ground-covering plant in the tundra. Lichens: symbiotic algae-fungi; survive extreme cold; important food for reindeer/caribou. Sedges and grasses: short, hardy plants. Dwarf shrubs: extremely low-growing (hugging the ground for warmth), such as dwarf willow and dwarf birch. No trees grow in the tundra: the growing season is too short, temperatures too low, and permafrost prevents deep roots. Concept Tested: Tundra vegetation: mosses, lichens, dwarf shrubs; no trees; permafrost; extremely cold short growing season

NDA 2016-II

Q. 4. The characteristic trees of the Savanna grasslands are:

(a) Pine and cedar

(b) Oak and maple

(c) Acacia and baobab

(d) Teak and bamboo

Answer: (c) Acacia and baobab

Explanation: The Savanna (tropical wet-dry) grassland is characterised by two iconic trees: Acacia: flat-topped, umbrella-shaped, thorny trees that are widely spaced across the savanna. Their flat crown is an adaptation to maximise sunlight interception in the open grassland. Baobab: bulbous-trunked trees that store water in their thick trunks to survive the long dry season. They can live for thousands of years and are sometimes called the “tree of life.” Pine and cedar = coniferous/taiga. Oak and maple = temperate deciduous. Teak and bamboo = tropical deciduous (including India). Concept Tested: Savanna characteristic trees: Acacia (flat-topped) and Baobab (water-storing); both drought-adapted

NDA 2015-I

Q. 5. Which one of the following is the world’s largest tropical rainforest?

(a) Congo Rainforest

(b) Amazon Rainforest

(c) Daintree Rainforest

(d) Southeast Asian Rainforest

Answer: (b) Amazon Rainforest

Explanation: The Amazon Rainforest is the world’s largest tropical rainforest, covering approximately 5.5 million km² across South America (primarily in Brazil, but extending into Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana). The Congo Rainforest in Central Africa is the second largest (~3.3 million km²). The Daintree Rainforest in Queensland, Australia, is the world’s oldest tropical rainforest (~180 million years old) but not the largest. Concept Tested: Amazon Rainforest: world’s largest tropical rainforest (~5.5 million km²); Congo = second largest

NDA 2013-I

Q. 6. The coniferous forests of the world are mainly composed of trees of which one of the following types?

(a) Deciduous broad-leaved trees

(b) Evergreen broad-leaved trees

(c) Needle-leaved evergreen trees

(d) Xerophytic trees

Answer: (c) Needle-leaved evergreen trees

Explanation: Coniferous forests (taiga/boreal forests) are dominated by needle-leaved evergreen trees: specifically conifers such as pine, spruce, fir, and larch. Needle-shaped leaves are adaptations to the harsh conditions of taiga: 1. Small surface area: reduces water loss and prevents heavy snow accumulation. 2. Waxy coating: protects against cold and desiccation. 3. Evergreen: retain leaves year-round; can photosynthesize during brief warm spells without waiting to grow new leaves. 4. Conical/pyramidal shape: helps snow slide off without breaking branches. Concept Tested: Coniferous forests (taiga): needle-leaved evergreen trees (pine, spruce, fir, larch); cold climate adaptations

NDA 2012-I

Q. 7. Deciduous trees are so called because they:

(a) Are very tall and straight

(b) Shed their leaves during a particular season

(c) Have needle-like leaves

(d) Never shed their leaves

Answer: (b) Shed their leaves during a particular season

Explanation: Deciduous trees shed their leaves during a particular season: either the cold winter (in temperate deciduous forests) or the dry season (in tropical deciduous forests). “Deciduous” comes from Latin decidere: to fall off. By shedding leaves, trees reduce water loss (transpiration) during periods when water is unavailable (due to drought or frozen ground). Examples: Oak, elm, maple, beech, teak, sal, bamboo. Contrast with Evergreen trees: they retain leaves throughout the year (e.g., conifers, tropical rainforest trees). Concept Tested: Deciduous trees: shed leaves seasonally (dry season or cold winter); reduce water loss during unfavourable periods

NDA 2011-I

Q. 8. Mangrove forests are generally found in:

(a) Temperate coastal regions

(b) Tropical and subtropical coastal wetlands

(c) Cold polar regions

(d) Temperate inland river banks

Answer: (b) Tropical and subtropical coastal wetlands

Explanation: Mangrove forests are salt-tolerant (halophytic) trees and shrubs that grow in intertidal coastal zones of tropical and subtropical regions: where freshwater rivers meet the sea. Key characteristics: 1. Found in sheltered coastlines: estuaries, deltas, lagoons. 2. Adapted to saline water, waterlogged soil, and tidal fluctuations (prop roots and pneumatophores for oxygen). 3. Major regions: Sundarbans (India/Bangladesh: world’s largest mangrove forest), Amazon delta, West Africa, Southeast Asia, Florida. Mangroves protect coastlines from erosion and storm surges and serve as nurseries for marine life. Concept Tested: Mangrove forests: tropical and subtropical coastal wetlands; salt-tolerant; tidal zones; Sundarbans

NDA 2009-II

Q. 9. Which one of the following forests shows the maximum biodiversity?

(a) Tropical rainforest

(b) Temperate deciduous forest

(c) Taiga

(d) Tropical dry forest

Answer: (a) Tropical rainforest

Explanation: Tropical rainforests have the highest biodiversity of any terrestrial ecosystem on Earth. Although they cover only about 6–7% of Earth’s land surface, they are estimated to contain more than 50% of the world’s plant and animal species. Reasons for high biodiversity: 1. Year-round warm temperatures and abundant rainfall support year-round growth. 2. Multiple distinct canopy layers (emergent, canopy, understorey, forest floor) create diverse ecological niches. 3. High stability over millions of years: species have had time to evolve and diversify. The Amazon rainforest alone is estimated to contain 10% of all species on Earth. Concept Tested: Tropical rainforest: highest biodiversity on Earth; covers ~6% of land but houses >50% of species

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