CG Board Class 9 Science Chapter 17 Solutions: Habitat (आवास) – 2026-27

(a) bats → millipede → kanimachri

(b) remains of dead organisms → kanimachri → bats

(c) bats → remains of dead organisms → kanimachri

(d) insects → bats → snails

(d) They change their habitat once in their lifetime but do not return to their permanent habitat /

• Correct Option / : (a) Producers / .

• English:
• Chosen Organism: Fish in a Freshwater Pond Habitat.
• Biotic Components:

1. Producers: Phytoplankton, submerged algae, and aquatic plants (e.g., Hydrilla) that convert sunlight into chemical energy.
2. Consumers: Zooplankton, aquatic insects, smaller fishes, and predatory birds/frogs.
3. Decomposers: Bacteria and fungi present in pond sediment that break down dead organic matter.

• Abiotic Components:

1. Water: Provides the liquid medium for movement and holds dissolved oxygen for respiration.
2. Dissolved Oxygen & Temperature: Crucial for physiological functioning and survival.
3. Sunlight: Enables photosynthesis in aquatic plants.

• Hindi:

• English:
• Essay Title: Survival Challenges on a Biotic-Deprived Island.
• Introduction: Life on Earth is based on a delicate web of interrelationships between biotic (living) and abiotic (nonliving) components. If a human reaches an island devoid of all other biotic components (plants, animals, fungi, bacteria), survival becomes immediately precarious.
• Immediate Challenges:

1. Lack of Food: Without plant producers or animal consumers, there would be no source of carbohydrates, proteins, or essential vitamins.
2. Oxygen Depletion: Without photosynthetic green plants, oxygen replenishment on a local scale would cease over time.
3. Accumulation of Organic Waste: In the absence of decomposers (bacteria and fungi), nutrient recycling would completely stop.

• Conclusion: Human survival is impossible in isolation from other living beings. This highlights the indispensable necessity of biodiversity and interspecies dependence in any functional habitat.
• Hindi:

• English:

Since the Moon lacks an atmosphere, liquid water, soil nutrients, and suitable gravitational/thermal conditions, the following artificial life-support systems must be supplied:

1. Pressurized Breathing Gas: Oxygen tanks or oxygen-generating units.
2. Water Supply & Recycling Units: Clean drinking water and water-purification apparatus.
3. Preserved Food & Hydroponic Greenhouse Systems: Packaged food supplies along with soil/hydroponic setups and plant seeds to generate food and oxygen continuously.
4. Pressurized Habitats & Spacesuits: Radiation-shielded, temperature-regulated living modules to protect against extreme cosmic cold/heat and vacuum.
5. Waste Recycling Units & Power Sources: Solar panels/nuclear generators and waste management systems.

• Hindi:

• English:
• Direct Food Chain with Bear (Omnivore):

Green Plants / Wild Berries → Bear → Decomposers.

Alternative Aquatic Chain: Aquatic Plants → Fish → Bear → Decomposers.

• Connecting to Form a Food Web:
• Chain A: Grass → Deer → Tiger / Bear.
• Chain B: Grass → Insects → Frog → Snake.
• Chain C: Wild Plants / Berries → Fish / Small Rodents → Bear.
• Chain D: Dead Organisms → Decomposers → Soil Nutrients → Plants.

Interconnection: Since the bear eats berries, fishes, and small mammals, it connects terrestrial, herbivorous, aquatic, and predatory food chains together into a complex food web.

• Hindi:

What special features of Kotumsar caves have been described in this section?

1. Kotumsar caves feature conical limestone formations known as stalactites and stalagmites.
2. The air temperature inside the cave remains between 25°C to 32°C throughout the year, and the water temperature ranges between 22°C to 30°C.
3. During rainy seasons, the caves get flooded with water.
4. The cave provides a dark, subterranean aquatic environment housing unique species like the blind fish “kani machri”.

Suppose kani machri flows out from the cave during floods, how do you think it will survive?

If kani machri flows out of the cave during floods, its survival outside becomes extremely difficult. Since it is adapted to complete darkness with poorly developed or vestigial eyes, exposure to bright sunlight and temperature fluctuations outside will disorient it. Furthermore, it will easily fall prey to surface predators like aquatic birds and larger fishes because it lacks defensive camouflage and visual awareness.

How do Kotumsar fishes differ from other fishes?

1. Vision: Kotumsar fishes (kani machri) have very small or vestigial eyes (blindness) due to living in dark caves, unlike normal fishes which have well-developed eyes.
2. Size: Their body size is quite small, ranging between 2 cm to 4 cm.
3. Feeding Habit: They function as scavengers in the cave, feeding on organic remains, detritus, and dead animals/plants.
4. Shelter: They live in soil burrows inside the dark cave aquatic system.

Answer / उत्तर:

1. अपरिहार्य अजैविक घटक: हवा (श्वसन हेतु ऑक्सीजन), जल (पाचन एवं जैविक क्रियाओं हेतु), सूर्य का प्रकाश (ऊर्जा का मुख्य स्रोत), मिट्टी तथा खनिज लवण।
2. अपरिहार्य जैविक घटक: हरे पौधे (उत्पादक जो भोजन एवं ऑक्सीजन देते हैं), जंतु (दूध, कृषि एवं पारिस्थितिक संतुलन हेतु) तथा सूक्ष्मजीव/अपघटक (जो पोषक तत्वों का पुनर्चक्रण करते हैं)।

What would be the impact on the food web if the bison becomes extinct?

If the bison (primary consumer) becomes extinct

1. The population of grass and plants (producers) will increase significantly due to lack of grazing pressure.
2. Predators like lions (secondary consumers) that feed on bisons will face acute food shortage, leading to a decline in their population or forcing them to hunt other herbivores.
3. The overall ecological balance of the forest habitat will be severely disrupted.

Draw two food chains including yourself and state the interrelation between them.

• Food Chain 1: Green Plants (Vegetables/Cereal) → Human (Primary Consumer).
• Food Chain 2: Grass/Fodder → Cow/Buffalo → Milk/Dairy Products → Human (Secondary Consumer).
• Interrelation: Humans act as omnivores occupying multiple trophic levels (primary consumer in chain 1 and secondary consumer in chain 2). This interconnects plant producers and animal husbandry into a single food web.

Make a food chain including organisms of Kotumsar caves.

Dead organic matter / Detritus → Kani Machri (Blind cave fish) → Bat.

What is the habitat of a Brahmi duck?

The Brahmi duck (Surkhaab) inhabits two distinct geographical regions during its life span

1. Summer Breeding Habitat: High altitude Himalayan regions of Ladakh, Sikkim, and Arunachal Pradesh near rivers, grasslands, and lakes located up to 5000 meters above sea level.
2. Winter Non-Breeding Habitat: Warmer wetland regions of Central and Southern India, including rivers and marshlands of Chhattisgarh.

Can Brahmi duck be considered as a migratory organism? Why?

Yes, the Brahmi duck is a migratory organism. It spends the summer months in the colder Himalayan regions for breeding, but with the onset of winter and depletion of food resources, it migrates to the warmer wetland habitats of Central and Southern India, returning back to its permanent breeding grounds every year.