1. What is the geological origin of the Himalayas?

The Himalayas are young fold mountains formed by the collision of the Indian plate with the Eurasian plate, resulting in uplift and folding.

2. Describe the Greater Himalaya (Himadri).

The Greater Himalaya is the highest range with perennial snow and major peaks; it hosts large glaciers and is the source of several major rivers.

3. What are the characteristics of the Lesser Himalaya?

The Lesser Himalaya (Himachal) has steep slopes, lower peaks than Himadri, is home to hill stations and supports terraced agriculture.

4. Explain the formation and features of the Siwalik range.

The Siwalik or Outer Himalaya is composed of unconsolidated sediments, has low elevation, and contains broad valleys called duns formed from deposited material.

5. How do Himalayan glaciers influence river systems?

Glaciers feed perennial rivers by releasing meltwater, ensuring sustained flows essential for irrigation and water supply downstream.

6. State two economic benefits of the Himalayas.

They provide water for irrigation and hydroelectric power, and support tourism and forestry industries.

7. What is an intermontane valley? Give an example.

An intermontane valley lies between mountain ranges; Dehradun in the Siwalik region is an example.

8. How do the Himalayas affect India's climate?

They block cold Central Asian winds, keeping northern India warmer in winter, and they help in bringing and trapping monsoon rainfall.

9. Mention one ecological concern related to the Himalayas.

Deforestation and glacier retreat due to climate change endanger biodiversity and reduce freshwater availability.

10. How did the Northern Plains of India originate?

They were formed by deposition of sediments (alluvium) carried by rivers from the Himalayas over geological time, creating a broad flat plain.

11. What are the subdivisions of the Northern Plains?

The plains are divided into the Punjab (upper) plains, the Ganga (central) plains, and the deltaic (lower/Bengal) plains.

12. Explain why alluvial soil is fertile.

Alluvial soil is rich in minerals and fine sediments deposited by rivers, which retains moisture and nutrients favourable for crops.

13. What role do rivers play in the Northern Plains' agriculture?

Rivers provide irrigation, replenish soils with fertile silt, and support multiple cropping cycles across the plains.

14. Describe the Bengal basin briefly.

The Bengal basin is a vast delta formed by the Ganga and Brahmaputra rivers, characterised by fine alluvium and high agricultural productivity.

15. Name two major crops grown in the Northern Plains.

Wheat and rice are major crops; sugarcane and pulses are also widely cultivated.

16. Why is population density high in the plains?

Fertile land, water availability, and historical settlement patterns have led to intensive agriculture and urbanisation, increasing population density.

17. What irrigation methods are commonly used?

Canal irrigation, tube wells and river diversion systems are commonly used to irrigate crops in the plains.

18. How do floods affect the Northern Plains?

Floods deposit fertile silt benefitting soil fertility but can cause loss of life, property and damage to crops and infrastructure.

19. What makes the Peninsular Plateau geologically stable?

It is composed of ancient crystalline igneous and metamorphic rocks that form a stable continental shield with little recent tectonic activity.

20. Differentiate between Central Highlands and Deccan Plateau.

The Central Highlands are located north of the Narmada with undulating uplands and hills, while the Deccan Plateau is a large triangular tableland south of the Narmada-Tapi region bounded by the Ghats.

21. Why are black soils important in the Deccan?

Black soils (regur) are moisture-retaining and rich in minerals, making them ideal for cotton cultivation and other crops.

22. Name major mineral resources of the plateau.

Iron ore, manganese, bauxite and copper are important minerals extracted from the Peninsular Plateau.

23. Describe the general drainage pattern of peninsular rivers.

Peninsular rivers generally have older drainage patterns, flow through shallow valleys, are seasonal and form wider basins; many flow eastwards into the Bay of Bengal.

24. What are the Deccan Traps?

Deccan Traps are extensive basaltic lava flows formed from volcanic activity, producing rich black soils in many areas.

25. How do peninsular rivers differ from Himalayan rivers?

Peninsular rivers are mostly seasonal with less water and sediment load, whereas Himalayan rivers are perennial and carry heavy silt from glaciers.

26. Give an example of industrial activity linked to the plateau's resources.

Iron and steel industries (e.g., Bhilai, Jamshedpur) are established near mineral-rich areas on the plateau.

27. What causes aridity in the Thar Desert?

Its location in a rain-shadow region with scanty rainfall and high evaporation leads to arid conditions; the Aravalli range also reduces moisture penetration.

28. Describe the soil and vegetation of the Thar.

Sandy soils with low organic matter; vegetation is xerophytic with thorny shrubs, grasses and scattered trees adapted to drought.

29. How do people adapt to desert conditions?

Through pastoralism, cultivating drought-resistant crops (millets), water conservation, and using wells and canal irrigation where available.

30. Mention one environmental challenge in the desert.

Desertification and overgrazing can degrade land, reducing productivity and biodiversity in fragile ecosystems.

31. What is the economic significance of the Thar region?

It supports pastoral livelihoods, some agriculture in irrigated tracts, tourism, and renewable energy projects like solar farms.

32. How are the coastal plains formed?

They are formed by the deposition of sediments brought by rivers and by the erosion of the western and eastern edges of the peninsular plateau, creating flat lowlands along the seacoast.

33. Contrast the Western and Eastern Coastal Plains.

The Western Coastal Plains are narrower and steeper with lagoons and estuaries, while the Eastern Coastal Plains are broader, flatter and include large river deltas.

34. Why are deltas fertile?

Deltas receive fine silts and nutrient-rich sediments from rivers that are deposited as the river slows near the sea, enriching the soil for agriculture.

35. Name two economic activities on coastal plains.

Fishing and port-related trade; tourism and agriculture (especially rice cultivation in delta areas) are also important.

36. What role do mangroves play on the coast?

Mangroves protect shorelines from erosion and storms, provide nursery grounds for fish and support coastal biodiversity (e.g., Sunderbans).

37. Give one reason why the western coast has many ports.

Its indented coastline with natural harbours and proximity to major trade routes makes it suitable for ports like Mumbai and Mangalore.

38. How do coastal plains influence climate locally?

They moderate temperatures, increase humidity, and influence local rainfall patterns through sea breezes and coastal weather systems.

39. Mention a soil type common on the eastern coastal plains.

Alluvial soils and fine silty soils in the deltaic regions are common on the eastern coastal plains.

40. What is a backwater? Provide an example.

A backwater is a lagoon or estuarine waterbody separated from the sea by sandbanks; the Kochi backwaters are a notable example on the west coast.

41. Where are the Andaman and Nicobar Islands located?

They are in the Bay of Bengal, closer to the eastern coast of India and form an arc near the Andaman Sea.

42. What is the primary origin of Lakshadweep islands?

Lakshadweep islands are coral atolls formed by reef-building corals on submerged volcanic bases in the Arabian Sea.

43. How do coral reefs form around islands?

Coral polyps secrete calcium carbonate and build reefs over time in warm, shallow seas, forming protective barriers and lagoons around islands.

44. Name two economic activities on the islands.

Fishing and tourism are major activities; coconut cultivation and pearl fishing are also important locally.

45. Why are the Andaman Islands ecologically significant?

They host rich evergreen forests, unique wildlife and marine biodiversity, including coral reefs and endemic species.

46. Mention one strategic advantage of India’s islands.

They allow control and surveillance over important sea lanes and enhance India’s maritime security presence in the Indian Ocean.

47. What are atolls and which group are they associated with?

Atolls are ring-shaped coral islands surrounding a lagoon; they are associated with the Lakshadweep group.

48. How do islands contribute to biodiversity?

Islands often have unique habitats and endemic species, contributing to greater regional biodiversity and specialized ecosystems.

49. What environmental threats face island ecosystems?

Rising sea levels, coral bleaching, coastal erosion, and human-induced habitat loss threaten island ecosystems.

50. Suggest one conservation measure for island regions.

Protecting coral reefs and mangroves, regulating tourism, and establishing marine protected areas help conserve island ecosystems.