Short Answer Questions
Q1: What are the different forms of water mentioned in the chapter?
Ans: Water exists in three forms: liquid (like rain or river water), solid (like ice or snow), and vapour (like steam or clouds). These forms change based on temperature, such as ice melting into liquid or water evaporating into vapour.
Q2: Why is freshwater important for living beings?
Ans: Freshwater is essential for drinking, growing crops, and daily activities. It supports life for people, animals, birds, and plants, as most of Earth’s water is salty and unfit for these purposes.
Q3: Explain the water cycle briefly.
Ans: The water cycle is the constant movement of water where heat turns liquid water into vapour, forming clouds. When cooled, it falls as rain or snow, returning to rivers, lakes, and oceans.
Q4: What is groundwater, and how is it accessed?
Ans: Groundwater is water stored deep underground after rain seeps through soil and rocks. It is accessed by digging wells, borewells, tube wells, or handpumps for human use.
Q5: How does the shape of the land affect river flow?
Ans: Rivers flow from higher to lower ground, following the land’s slopes and curves. They may spread out or collect in areas, forming lakes or valleys, as shown in activities like the mustard seed experiment.
Q6: Name some animals adapted to live in freshwater.
Ans: Animals like the fishing cat with webbed paws, the water scorpion with a breathing tube, and the pond heron with long legs are adapted to freshwater. They have features for swimming, breathing, or catching prey.
Q7: What are the types of plants found in water bodies?
Ans: Water plants include edge plants like reeds, rooted floating plants like lotus, and free-floating plants like water hyacinth. These adaptations help them survive in aquatic environments.
Q8: Why do some areas have less groundwater recharge?
Ans: In cities with cemented surfaces, rainwater cannot seep into the soil easily, reducing recharge. Open areas, trees, and soak pits help water return underground.
Q9: Describe an activity showing water forms.
Ans: Place ice in a steel glass; droplets form on the outside from air moisture condensing. This shows solid ice melting to liquid and vapour turning back to liquid.
Q10: How do aquatic plants like lotus stay healthy?
Ans: Aquatic plants have waxy coatings on leaves to make them waterproof, preventing excess water entry. This protects them from damage in wet environments.
Long Answer Questions
Q1: Explain the importance of the water cycle and how it sustains life on Earth.
Ans: The water cycle is crucial as it recycles water continuously through evaporation, condensation, and precipitation.
- Heat from the sun turns water into vapour, forming clouds that release rain or snow, replenishing rivers and lakes.
- This process provides freshwater for drinking, agriculture, and ecosystems.
- Without it, water sources would dry up, affecting plants, animals, and humans.
- It also helps in weather patterns and prevents droughts or floods.
Q2: Discuss the challenges of freshwater availability and ways to conserve it.
Ans: Most Earth water is salty, leaving limited freshwater for all life.
- Overuse, pollution, and cemented cities reduce groundwater recharge, leading to shortages.
- Conservation methods include rainwater harvesting, fixing leaks, and planting trees to allow soil absorption.
- Using soak pits and avoiding waste helps recharge groundwater.
- Communities can build small dams or ponds to store rainwater, ensuring sustainable use for future generations.
Q3: Describe adaptations of animals and plants in freshwater habitats.
Ans: In freshwater, animals like fishing cats have webbed paws for swimming, while pond herons use long legs to catch fish.
- Insects like water scorpions breathe via tail tubes.
- Plants adapt with floating leaves (lotus) or waxy coatings to stay waterproof.
- Rooted plants anchor in pond beds, and free-floating ones like hyacinth spread on surfaces.
- These features help them thrive in water, maintaining balance in ecosystems.
Q4: How does water shape the land and influence river paths in India?
Ans: Water flows from mountains to seas, carving valleys and forming deltas.
- Rivers like Godavari follow land slopes, eroding soil and creating features like waterfalls or dunes.
- In India, rivers flow east to the Bay of Bengal or west to the Arabian Sea, guided by mountains like the Western Ghats.
- This shapes landscapes, supports agriculture, and creates habitats, but can cause floods if not managed.
Q5: What role do human activities play in affecting water bodies, and how can we protect them?
Ans: Human actions like pollution, deforestation, and concretisation reduce water quality and recharge, harming aquatic life.
- For example, cemented areas prevent rainwater absorption, causing shortages.
- Protection involves planting trees, creating soak pits, and avoiding waste dumping.
- Community efforts like building johads in Rajasthan recharge groundwater.
- Educating on conservation ensures clean water for ecosystems and future use.