Model Answer

Biome is a geographical region characterized by distinct plant and animal communities. The defining factors of biomes include climate conditions such as rainfall, temperature, humidity, and soil type, which influence the types of species that can thrive in these environments.

Biomes of the World

1. Aquatic Biomes
   • Freshwater biomes include lakes, rivers, and ponds with less than 1% salt content.
   • Marine biomes cover 75% of Earth’s surface, including oceans, coral reefs, and estuaries, which are vital for marine biodiversity.
2. Grasslands
   • Dominated by grasses and found in regions with warm, dry climates.
   • Tropical grasslands (Savannas) are near the equator and have scattered trees.
   • Temperate grasslands are further from the equator, with few trees and less rainfall, examples include prairies and steppes.
3. Forests
   • Tropical forests are warm and humid, near the equator, rich in biodiversity.
   • Temperate forests experience four seasons and are found at higher latitudes.
   • Boreal forests (Taiga) are cold, with long winters and are located in high latitudes, mainly in northern parts of the globe.
4. Deserts
   • Dry regions with less than 50 cm of rainfall annually. Deserts cover about 20% of Earth’s surface and host specially adapted wildlife like reptiles and small mammals.
   • They are categorized into hot and dry, semiarid, coastal, and cold deserts.
5. Altitudinal Biomes
   • Arctic and alpine biomes have harsh conditions, with temperatures ranging from -34 to 12°C and minimal precipitation.
   • Vegetation is limited to shrubs, mosses, and lichens due to poor soil quality and permafrost, which inhibits plant growth.

These biomes are shaped by climate, influencing biodiversity and adaptation strategies of the species within them.

Model Answer

The sugar industry in India is a significant agro-based sector impacting the livelihood of approximately 50 million farmers and 5 lakh mill workers. India, the second-largest sugar producer globally after Brazil, has 732 sugar factories as of 2017, generating an annual output worth ₹80,000 crores.

• Northern India:
  • Uttar Pradesh: The Ganga-Yamuna doab and Tarai regions dominate sugarcane production.
  • Punjab and Haryana: Sugar mills operate near major agricultural belts.
  • Bihar and Madhya Pradesh: Smaller contributions to sugar output.
• Southern India:
  • Tamil Nadu: Coimbatore, Vellore, and Tiruchchirappalli districts are prominent.
  • Karnataka: Belagavi, Ballari, and Mandya districts lead production.
  • Andhra Pradesh and Telangana: Coastal districts such as East and West Godavari and Nizamabad are key producers.
• Western and Other Regions:
  • Maharashtra: A major producer, with sugar factories well-integrated with cane cultivation.
  • Gujarat: A relatively new entrant to the industry.

Reasons for the Shift from Northern to Southern India

The sugar industry has gradually shifted southward due to the following factors:

1. Tropical Climate:
   • Southern India’s tropical conditions allow for higher yield and better-quality sugarcane with higher sucrose content compared to the subtropical north.
2. Longer Crushing Seasons:
   • The south benefits from a 7-8 month crushing season (October–May), unlike the north, which has a shorter 4-month period (November–February).
3. Crop Quality and Efficiency:
   • Southern sugar mills are newer, better equipped with modern machinery, and managed more efficiently under cooperative models.

These advantages, coupled with surplus production and government initiatives, have positioned Southern India as the emerging hub of sugar production.

मॉडल उत्तर

पृथ्वी का वायुमंडल विषुवत वृत्त (गर्म) और ध्रुवों (ठंडा) के बीच तापीय अंतर के कारण गतिशील है। वायुमंडलीय परिसंचरण वह प्रक्रिया है जिससे पवनें विशेष प्रतिरूप में चलती हैं। यह परिसंचरण कई कारकों पर निर्भर करता है:

• अक्षांशीय तापमान भिन्नता
• वायुदाब पट्टियों की स्थिति
• सौर किरणों के साथ वायुदाब पट्टियों का विस्थापन
• महाद्वीपों और महासागरों का वितरण
• पृथ्वी का घूर्णन

वायुमंडलीय परिसंचरण का कार्य

वायुमंडलीय परिसंचरण का मूल स्रोत विषुवत वृत्त का उच्च तापमान है। यहाँ गर्म वायु ऊपर उठती है, निम्न वायुदाब का निर्माण करती है, और वर्षा होती है। यह वायु क्षोभमंडल की सीमा पर जाकर ठंडी होकर ध्रुवों की ओर बढ़ती है। 30° उत्तर और 30° दक्षिण अक्षांश पर यह वायु नीचे आती है, जिससे उच्च वायुदाब और शुष्क क्षेत्र बनते हैं।

प्रमुख वायु परिसंचरण कोष्ठ

1. हेडले कोष्ठ
   • विषुवत वृत्त से गर्म वायु ऊपर उठती है।
   • 30° अक्षांश पर ठंडी वायु नीचे उतरती है।
   • इस क्षेत्र की पूर्वी व्यापारिक पवनें पवनों के चक्र को पूर्ण करती हैं।
2. ध्रुवीय कोष्ठ
   • ध्रुवों पर ठंडी वायु नीचे आती है।
   • यह वायु लगभग 70° अक्षांश तक चलती है और फिर ऊपर उठती है।
   • ध्रुवीय पवनें पूर्व से पश्चिम की ओर प्रवाहित होती हैं।
3. फैरल कोष्ठ
   • यह हेडले और ध्रुवीय कोष्ठ के बीच स्थित होता है।
   • 30° से 60° अक्षांश तक पछुआ पवनें चलती हैं।
   • यहाँ तूफान और अवदाब क्षेत्र प्रमुख हैं।

महासागरों और वायुमंडल का संबंध

महासागर वायुमंडलीय परिसंचरण को ऊर्जा और जल वाष्प प्रदान करते हैं। महासागरीय धाराएँ पवनों से प्रभावित होती हैं, जिससे वैश्विक जलवायु संतुलन में योगदान होता है।

निष्कर्ष

वैश्विक वायुमंडलीय परिसंचरण पृथ्वी की जलवायु, वर्षा, और तापमान को संतुलित करता है। यह प्रणाली धरती के समग्र पारिस्थितिकी तंत्र के लिए महत्वपूर्ण है।

Model Answer

Coal is a vital and abundant fossil fuel in India, comprising more than 50% of the nation’s energy requirements. India’s coal reserves are primarily divided into two categories: Gondwana and Tertiary coal fields.

Gondwana Coal Fields

• Overview: The Gondwana coal fields are the most significant in India, accounting for about 98% of the nation’s coal reserves and nearly 99% of its coal production. These coal fields, approximately 250 million years old, are primarily located in the peninsular region.
• Major Coal-Producing States:
  • Jharkhand: Holds over 28% of the coal reserves and contributes more than 20% of the country’s coal production. Key coalfields include Jharia, Bokaro, and Rajmahal.
  • Odisha: With 24.64% of coal reserves, Odisha is the second-largest state in terms of reserves and the third-largest producer, contributing about 19% of India’s coal output. The Talcher coalfields are significant.
  • Chhattisgarh: Contains 16% of India’s coal reserves and produces over 21% of the coal. Prominent coalfields include Korba and Tatapani.
  • West Bengal: Holds 11% of the reserves but produces just over 4%. The Raniganj coalfield is the largest in the state.
  • Madhya Pradesh: Contributes about 13% of India’s coal production with 8% of the reserves. Major coalfields include Singrauli and Jhingurda.
  • Andhra Pradesh and Telangana: These states hold 7% of the reserves and produce around 10% of the coal. The Godavari Valley coalfields are central to their coal production.
  • Maharashtra: Although only possessing 3% of the reserves, Maharashtra produces over 7% of India’s coal, with Kamptee coalfields being significant.

Tertiary Coal Fields

• Overview: The Tertiary coal fields, which are younger (15 to 60 million years old), contribute only about 1% to the nation’s total coal production.
• Locations: These coalfields are found in states like Assam (Makum, Nazira), Meghalaya (Garo, Khasi, Jaintia hills), Arunachal Pradesh (Namchick-Namrup), Jammu and Kashmir (Udhampur, Kalakot), and Himachal Pradesh (Chamba district).

Lignite Coal

• Overview: Lignite, a form of coal with lower carbon content, has seen increased production in India. Tamil Nadu is the major producer, with the Neyveli coalfields accounting for 90% of the nation’s lignite reserves.
• Other States: Lignite deposits are also found in Gujarat, Jammu and Kashmir, Kerala, Rajasthan, West Bengal, and Puducherry.

Conclusion

India’s coal resources are heavily concentrated in the Gondwana coal fields, especially in states like Jharkhand, Odisha, and Chhattisgarh, which are key contributors to the country’s energy needs.

Model Answer

Plate tectonics explains how the Earth’s lithosphere is divided into massive slabs, called tectonic plates, that shift over time. These plates interact at various types of boundaries, which are categorized as convergent, divergent, and transform boundaries.

Convergent Boundaries

• Description: Convergent boundaries occur when two plates collide, leading to various geological events.
• Effects: The collision can cause the edges of the plates to buckle into mountain ranges or result in one plate sinking into the Earth’s mantle, forming a subduction zone. This often leads to the creation of volcanoes and deep ocean trenches. Earthquakes are also common in these areas.
• Examples: Convergence can happen between oceanic and continental plates (e.g., the Andes), two oceanic plates (e.g., the Marianas Trench), or two continental plates (e.g., the Himalayas).
• Crust Interaction: At these boundaries, oceanic crust is destroyed as it sinks into the mantle, while continental crust is created as magma rises and solidifies into granite.

Divergent Boundaries

• Description: Divergent boundaries are formed when two tectonic plates move away from each other, creating space for new crust to form.
• Effects: As plates separate, magma from the mantle rises and solidifies, forming new oceanic crust. Earthquakes are frequent in these regions as the plates move apart.
• Examples: The Mid-Atlantic Ridge is a prominent example of a divergent boundary where new crust is continuously generated.

Transform Boundaries

• Description: Transform boundaries occur when two plates slide past each other horizontally.
• Effects: As the plates grind along, the boundary is often marked by fault valleys or undersea canyons. This movement causes earthquakes, but unlike convergent or divergent boundaries, the crust is neither created nor destroyed here.
• Examples: The San Andreas Fault in California is a well-known transform boundary.

Conclusion

The movement of tectonic plates at these boundaries shapes much of the Earth’s surface, contributing to the formation of mountains, volcanoes, and earthquakes. Each boundary type plays a distinct role in the planet’s dynamic geological processes.