NCERT Solutions Class 5 EVS Our Wondrous World Chapter 01 Water The Essence of Life

Question 1. Do you think we can drink the water present in the oceans?
Answer: Ocean water is not safe to drink because it has a very high salt content. Consuming it can make you unwell due to the amount of salt in it. Your body would not be able to handle so much salt without getting harmed.
In simple words: Ocean water has too much salt in it, so we cannot drink it.

Exam Tip: Always mention the salt content and its harmful effects on the body when answering about ocean water.

Question 2. What can ocean water be used for?
Answer: Ocean water serves several useful purposes. Salt can be extracted from ocean water through a process. Large factories use ocean water as a coolant for their machines. Additionally, people can clean and treat ocean water using special equipment to make it suitable for use, though this process requires advanced technology.
In simple words: Ocean water can be used to get salt, to cool machines in factories, and can be cleaned with special machines to drink it.

Exam Tip: Remember to list at least three uses of ocean water and mention that desalination (cleaning) requires special machines.

Question 3. Where can we find freshwater? Identify the different freshwater sources from the images given below and write their names.
Answer: Freshwater comes from many sources on Earth. Ponds are shallow water bodies found in low-lying areas. Lakes are large water bodies that form in mountains and valleys. Rivers flow from mountains towards oceans and are major sources of freshwater. Glaciers are frozen masses of ice in cold regions that contain freshwater. Canals are man-made channels built to transport water. Wells are holes dug into the ground to reach groundwater. Rain water is collected directly from rainfall and is pure freshwater at its source.
In simple words: Freshwater comes from ponds, lakes, rivers, glaciers, wells, canals, and rain.

Exam Tip: Make sure to name all nine sources shown in the diagram and distinguish between natural (ponds, lakes, rivers, glaciers, rain) and man-made (canals, wells) sources.

Question 4. (a) Where do these water droplets come from?
Answer: The water droplets that form on a cold glass come from the surrounding air. When a cold glass touches warm air, the water vapour in the air loses energy and changes into tiny water droplets on the glass surface. This happens because of the temperature difference between the glass and the air around it.
In simple words: Water droplets on the cold glass come from the air. Cold air makes the water vapour turn into droplets.

Exam Tip: This process is called condensation - mention that water vapour turns into liquid water when it cools down.

Question 4. (b) What happens to the ice cubes after they are left in the glass for some time?
Answer: The ice cubes gradually turn into water as time passes. This occurs because the room temperature causes the ice to absorb heat energy, which breaks apart the ice's solid structure and transforms it into liquid water.
In simple words: Ice cubes slowly melt and become water because of the warm temperature around them.

Exam Tip: This process is called melting - ice (solid) changes into water (liquid) when heated.

Question 4. (c) If we heat water, what will happen to it?
Answer: When you apply heat to water, it begins to boil and transforms into steam. Steam is the gaseous form of water that rises into the air as the water absorbs more and more heat energy.
In simple words: When water gets hot, it boils and turns into steam, which is water as a gas.

Exam Tip: This process is called evaporation or boiling - water (liquid) changes into steam (gas) when heated.

Question 5. What forms of water do you see in the above activity?
Answer: The activity demonstrates all three forms that water can take. Ice represents the solid state of water. The melted water in the glass is the liquid form. The steam rising from heated water shows the gaseous form, also called water vapour.
In simple words: Water exists as a solid (ice), liquid (water), and gas (steam).

Exam Tip: Always remember the three states of water - solid (ice), liquid (water), and gas (steam/vapour) - and be able to describe how each one forms.

Question 6. Observing Changes - Ice melting
Answer: When ice is heated, it transforms from its solid state into liquid water. The heat energy breaks the fixed structure of ice, causing it to melt and take the form of water.
In simple words: Ice changes into water when it is heated.

Exam Tip: This is the process of melting - state the change clearly by mentioning both the starting form (ice) and the ending form (water).

Question 7. Observing Changes - Water boiling
Answer: When water is heated to a high temperature, it begins to boil and converts into steam. The heat energy causes the water molecules to move rapidly and escape into the air as a gas.
In simple words: Water turns into steam when it is boiled.

Exam Tip: This is the process of evaporation - clearly state that liquid water becomes gas (steam) when heated.

Question 8. Observing Changes - Water in sunlight for three days
Answer: When water is left exposed to sunlight over a period of three days, part of it gradually evaporates and disappears into the air. The sun's energy causes the water to slowly transform into water vapour and escape.
In simple words: Water slowly dries up when left in the sun.

Exam Tip: This demonstrates natural evaporation - water disappears gradually due to the sun's heat, even without boiling.

Question 9. Activity 3 - Observe the bag in sunlight: Water heats up
Answer: When a sealed bag filled with coloured water is placed in direct sunlight, the water inside gets warmer due to the sun's rays passing through the transparent bag. The sun's energy transfers heat to the water, causing its temperature to rise gradually.
In simple words: The water in the bag gets warm because sunlight heats it up.

Exam Tip: Explain how sunlight acts as an energy source and causes heating inside the sealed bag.

Question 10. Activity 3 - Observe the bag in sunlight: Where did the water droplets come from?
Answer: As the water inside the sealed bag heats up, some of it evaporates and turns into water vapour. When this warm water vapour touches the cooler inner surface of the bag, it changes back into tiny water droplets through condensation. These droplets collect on the inside of the bag.
In simple words: Water vapour forms when the water heats up, then cools and turns into droplets on the bag.

Exam Tip: This activity shows the water cycle in miniature - evaporation followed by condensation - within a sealed system.

Question 11. Activity 4 - Take a transparent glass, fill half of it with soil, slowly pour water into the soil using a spoon, and observe what happens.
Answer: When you pour water slowly into soil, the water gradually disappears from the surface because the soil absorbs it. The water seeps downward through the tiny spaces between soil particles. Some water collects at the bottom of the glass. This experiment shows how rainwater enters the ground in nature. The water that travels deep underground becomes groundwater, which people later extract using wells, borewells, and handpumps. The activity teaches us why open spaces and green areas are important for allowing water to recharge underground supplies. In cities with concrete and cemented roads, water cannot soak into the ground easily, leading to waste or flooding problems.
In simple words: Water soaks into soil and moves down through tiny spaces. This water underground is called groundwater, which we use from wells.

Exam Tip: Mention percolation (water soaking through soil), groundwater formation, and the importance of permeable surfaces for water management in urban areas.

Question 12. Match the following: (i) Ocean water (a) Solid form of water (ii) Snow (b) Vapour form of water (iii) Steam (c) Not fit for drinking (iv) Rainwater (d) Freshwater
Answer:
(i) Ocean water - (c) Not fit for drinking
(ii) Snow - (a) Solid form of water
(iii) Steam - (b) Vapour form of water
(iv) Rainwater - (d) Freshwater
In simple words: Match each type of water with its correct description by pairing them correctly.

Exam Tip: Remember that ocean water contains salt and is not drinkable, snow is frozen water, steam is water gas, and rainwater is pure freshwater.

Question 13. Why do you think most of the water on Earth cannot be used for drinking or farming?
Answer: The majority of Earth's water is located in the oceans and contains high levels of salt, making it unsuitable for human consumption or agricultural use. Only a tiny fraction of Earth's water is freshwater, which is what we need for drinking and growing crops. The vast amount of salt in ocean water makes it harmful to drink and also damages crops if used for farming.
In simple words: Most water on Earth is salty ocean water, which we cannot use. Only a small amount is freshwater.

Exam Tip: Mention the percentage of salt water (about 97%) versus freshwater (about 3%) to support your answer.

Question 14. Large number of living beings live near water bodies. Why?
Answer: All living creatures - including animals, birds, fish, and people - settle near water bodies because water is essential for survival. Water is needed for drinking to maintain life. It is also used for bathing and cleaning. Water supports agricultural activities and farming. Plants and animals depend on water for growth and development. Water provides a habitat for aquatic life. Without water nearby, it would be difficult for any living being to survive.
In simple words: Living things need water to drink, eat, and stay alive, so they live near water bodies.

Exam Tip: List multiple reasons - drinking, bathing, farming, growth of plants and animals, and habitat for aquatic life.

Question 15. What would happen if it did not rain in your region for two years?
Answer: A prolonged drought lasting two years would cause severe consequences for the region. Rivers and ponds would dry up completely due to lack of rainfall to replenish them. The shortage of water would make it impossible to have enough drinking water for people. Crops could not be grown because there would be no water for irrigation and farming. Livestock and wild animals would suffer from lack of water. The region would face a serious drought situation, and life would become extremely difficult for all living beings. Economic activities would be severely disrupted, and people might need to migrate to areas with water.
In simple words: Without rain for two years, there would be no water to drink or grow crops, and life would be very hard.

Exam Tip: Describe the cascading effects - drying up of water bodies, crop failure, water scarcity, and drought conditions.

Question 16. What do you think happens to rainwater in a forest compared to a city?
Answer: Rainwater behaves very differently in forests and cities. In forested areas, the ground is permeable and covered with vegetation, allowing rainwater to soak easily into the soil and recharge the underground water sources. The trees and plants help absorb water and slow down its flow. However, in cities, most surfaces are covered with cement, concrete, and asphalt roads, which are impermeable. This prevents water from soaking into the ground, causing it to either be wasted as runoff or accumulate and cause flooding problems. Urban areas lose the opportunity to recharge groundwater supplies because of these hard surfaces.
In simple words: In forests, rain soaks into the soil, but in cities with cement roads, water cannot go down and gets wasted or causes floods.

Exam Tip: Contrast natural permeability of forest soil with impermeability of urban concrete surfaces and their effects on groundwater and flooding.

Question 17. Can you design a house or school that conserves water wisely? What would it include?
Answer: A water-efficient house or school would incorporate several features for conservation. Rainwater harvesting systems would collect water from roofs during rainfall for later use. Soak pits would allow water to percolate into the ground slowly rather than running off as waste. Open ground areas with grass and more trees would be maintained to allow natural water absorption. Taps and faucets would have automatic closing mechanisms to prevent water wastage. Stored rainwater could be reused for cleaning and other non-drinking purposes. These design choices would reduce overall water consumption and help recharge groundwater supplies while minimizing environmental impact.
In simple words: A good building saves water by catching rain, having gardens, and using taps that close by themselves.

Exam Tip: Include at least four features - rainwater harvesting, soak pits, green spaces, and water-efficient fixtures - to show comprehensive planning.

Question 18. What is the solid form of water called?
Answer: The solid form of water is called ice. Ice forms when water freezes at temperatures below 0 degrees Celsius. Ice exists naturally in many places, such as in glaciers found in high mountain regions, in ice cubes made in freezers, and as snow on the ground in cold climates. When temperatures drop sufficiently, liquid water loses energy and solidifies into ice.
In simple words: Ice is frozen water that forms when temperature is very cold.

Exam Tip: Define ice clearly and give examples of where it is found naturally (glaciers, snow) and artificially (ice cubes).

Question 19. Why can't we drink ocean water?
Answer: Ocean water contains very high concentrations of dissolved salts and various minerals throughout its volume. This salt content makes the water hazardous for human consumption. Drinking ocean water would make a person sick because the human body cannot safely process such large quantities of salt. The salt would actually draw water out of body cells, leading to dehydration and serious health problems rather than relieving thirst.
In simple words: Ocean water has too much salt in it, and drinking it makes people sick.

Exam Tip: Explain both the high salt concentration and the harmful physiological effects on the human body.

Question 20. What is the continuous movement of water in nature called?
Answer: The continuous movement of water from Earth's surface to the atmosphere and back again is called the water cycle. This natural process includes evaporation, where water from lakes and oceans turns into vapour. Condensation occurs when this vapour cools and forms clouds. Precipitation happens when water falls back to Earth as rain or snow. These processes repeat continuously, cycling water around our planet endlessly.
In simple words: The water cycle is when water goes up as vapour, forms clouds, and comes back down as rain.

Exam Tip: Name all three main stages - evaporation, condensation, and precipitation - and explain that this cycle repeats continuously.

Question 21. Which river flows into the Arabian Sea?
Answer: The Narmada River is a major river in India that flows in a westward direction and empties into the Arabian Sea. Unlike most other Indian rivers that flow towards the Bay of Bengal, the Narmada takes a different route to the west. It is one of the significant few rivers in India that does not follow the typical eastward flow pattern.
In simple words: The Narmada River flows west and goes into the Arabian Sea.

Exam Tip: Remember that the Narmada is exceptional among Indian rivers because it flows westward rather than eastward like most other major rivers.

Question 22. What helps fish to swim in water?
Answer: Fish use their fins to move through water and swim efficiently. Fins are specialized body parts that help fish move forward in any direction. Fins also enable fish to turn, steer, and maintain proper balance while underwater. The different types of fins serve various purposes - some help with forward motion while others assist with stability and directional changes. Without fins, fish would not be able to navigate through water effectively.
In simple words: Fish use fins to swim and move in water easily.

Exam Tip: Explain the specific functions of fins - movement, turning, steering, and balance - rather than just naming them.

Question 23. What type of water do most living beings need to survive?
Answer: Most living beings require freshwater to stay alive. Freshwater is essential for drinking, which is the most basic need for all life. It is also used for bathing and maintaining hygiene. Freshwater supports farming and agriculture, providing food for people. Plants and animals depend on freshwater sources for their survival and growth. Freshwater is found in rivers, ponds, lakes, and in the form of rainwater. Unlike salty ocean water, freshwater is safe for consumption and use by living organisms.
In simple words: All living things need freshwater to drink and survive.

Exam Tip: Distinguish between freshwater (safe for drinking and agriculture) and saltwater (unsuitable for living beings).

Question 24. What is groundwater?
Answer: Groundwater is rainwater that soaks into the soil after falling from the sky. This water travels downward through the tiny spaces between soil and rock particles until it accumulates in underground layers. Groundwater collects between different layers of soil and rock deep beneath the ground. People access this underground water by drilling wells or using handpumps, which draw water up from these deep underground sources. Groundwater is an important freshwater resource for many communities.
In simple words: Groundwater is rainwater that goes deep underground and is used through wells.

Exam Tip: Explain the process of how rainwater becomes groundwater and how it is accessed for human use.

Question 25. What helps rainwater seep into the ground?
Answer: Open spaces and permeable surfaces help rainwater soak into the ground. Green lawns with grass allow water to pass through and reach the soil below. Natural soil in fields and gardens absorbs water easily due to its porous nature. Forests with vegetation and exposed earth are especially good at allowing water infiltration. This process is crucial for recharging underground water supplies. In forests and villages where natural surfaces dominate, rainwater can seep down and recharge groundwater effectively. Without these open, permeable spaces, water cannot penetrate the ground.
In simple words: Grass, soil, and green areas help rainwater soak into the ground.

Exam Tip: Emphasize the importance of permeable surfaces and green spaces for groundwater recharge, especially in contrast to hard urban surfaces.

Question 26. Which aquatic plant floats freely and spreads quickly?
Answer: Water hyacinth is an aquatic plant that floats freely on water surfaces without needing to be rooted in soil. This plant grows very rapidly and spreads across ponds and lakes quickly. Water hyacinth does not require soil to survive since it floats on the water and draws nutrients from the water itself. Because of its fast growth and easy spread, water hyacinth can cover large areas of water bodies, sometimes becoming a problem if left unchecked.
In simple words: Water hyacinth is a plant that floats on water and grows very fast.

Exam Tip: Mention that water hyacinth floats freely, grows quickly, and doesn't need soil - these are its key distinguishing features.

Question 27. Why is the waxy coating on lotus leaves useful?
Answer: The waxy coating on lotus leaves serves a protective function by making the leaves waterproof. This special coating prevents excessive water from soaking into the plant tissue. The waxy surface causes water to form droplets that roll off rather than being absorbed. This helps the lotus leaf remain healthy and prevents waterlogging of the plant. The lotus can float on water without getting damaged or waterlogged because of this protective waxy layer. This adaptation allows the lotus to thrive in wet aquatic environments while staying dry on the surface.
In simple words: The waxy coating makes lotus leaves waterproof so they don't get too wet.

Exam Tip: Explain that the waxy coating is an adaptation that prevents water damage and allows the plant to survive in aquatic environments.

Question 28. Why can't rainwater enter the ground easily in cities?
Answer: Cities are largely covered with hard, impermeable surfaces such as cement, concrete, and asphalt used for roads and buildings. These artificial materials do not allow water to penetrate through them into the soil below. Since most of the ground is sealed by these hard surfaces, rainwater cannot soak into the earth and recharge groundwater sources. Instead, the water runs off as surface flow or collects in areas, sometimes causing flooding. This urban development pattern prevents the natural process of groundwater recharge that happens in areas with natural, permeable soil.
In simple words: Cities have cement and concrete roads that stop water from soaking into the ground.

Exam Tip: Contrast permeable natural surfaces with impermeable urban surfaces and explain the impact on groundwater recharge.

Question 29. What happens when water is heated?
Answer: When water is heated, it undergoes a change of state. The water absorbs heat energy and begins to boil vigorously. As the boiling continues, the liquid water transforms into steam, which is the gaseous form of water. This steam rises into the air as hot gas. The process of water changing into steam is part of the natural water cycle and helps form clouds in the atmosphere. Heating causes water molecules to gain energy and escape as vapour.
In simple words: When water gets hot, it turns into steam and rises into the air.

Exam Tip: Describe the phase change from liquid to gas and explain that steam is water in its gaseous form.

Question 30. What happens when steam cools down?
Answer: When steam comes into contact with cooler air or surfaces, it loses heat energy and undergoes a change. The gaseous steam transforms back into tiny liquid water droplets through a process called condensation. These droplets are visible as mist or moisture on surfaces. The condensation process is important in forming clouds in the sky when water vapour cools in the upper atmosphere. This condensed water eventually falls back to Earth as precipitation in the form of rain, snow, or hail, completing part of the water cycle.
In simple words: When steam cools down, it turns back into water droplets.

Exam Tip: Explain the condensation process and its role in cloud formation and the return of water to Earth as precipitation.

Question 31. What did students observe in the mustard seed activity?
Answer: In the mustard seed activity, students noticed that when mustard seeds were placed on a slope or uneven surface, they rolled downward following the shape and contours of the land. The seeds naturally collected and gathered in the low-lying areas and valleys where the slope ended. This behaviour of seeds mimics exactly how water behaves in nature. Water also flows downhill following the land's shape, and it collects in low areas to form rivers, lakes, and ponds, just as the seeds accumulated in the valleys. This activity helps demonstrate the principle of gravity and water flow in a simple, observable way.
In simple words: Mustard seeds rolled down slopes and collected in low areas, just like water flows in rivers.

Exam Tip: Connect the movement of seeds to the movement of water, showing how both follow gravity and land shape.

Question 32. Why is water called a lifeline?
Answer: Water is referred to as a lifeline because every living organism on Earth depends on it for survival. Humans need water for drinking, cooking, bathing, and farming crops that provide food. Animals require water to drink and maintain their body functions. Birds need water for drinking and maintaining feather health. Plants depend on water for growth, nutrition, and photosynthesis. Without water, there would be no life as we know it on our planet. Water is the most essential resource that connects all living things and enables life to exist and flourish. It is truly the foundation of all life on Earth.
In simple words: Water is called a lifeline because all living things need it to live.

Exam Tip: Emphasize that water is essential for all forms of life - humans, animals, birds, and plants - making it indispensable for existence.

What are the three forms of water and how do they change from one form to another?

Answer: Water exists naturally in three distinct forms:

Solid Form - Ice: This is the hard, frozen state of water. Ice forms when water is cooled to temperatures below 0 degrees Celsius. Ice is found in glaciers, ice cubes, and snow in cold regions.

Liquid Form - Water: This is the most common state we use daily for drinking, cooking, and bathing. Liquid water is found in rivers, ponds, lakes, and oceans.

Gaseous Form - Steam or Water Vapour: This is water in its invisible gas form. Steam forms when water is heated and boils, rising into the air. Water vapour is also present in the air around us.

Changes Between Forms:
Melting - Ice changes into water when heated by applying warmth.
Evaporation - Water transforms into steam or water vapour when boiled or heated by the sun.
Condensation - Steam cools down and turns back into water droplets, forming clouds or mist.
Freezing - Water becomes ice when cooled to very low temperatures.

In simple words: Water can be ice, water, or steam. Heating changes ice to water to steam. Cooling changes steam back to water to ice.

Exam Tip: Remember all four processes - melting, evaporation, condensation, and freezing - and be able to describe what causes each change.

Why is most of Earth's water not fit for drinking?

Answer: The vast majority of water on Earth, approximately 97%, is located in oceans and contains high levels of salt and minerals. Salty water is unsuitable for human consumption because drinking it would make people sick, and it cannot be used for farming crops. Out of the remaining small portion (about 3%) that is freshwater, most of it is frozen solid in glaciers and polar ice caps in extremely cold regions. The frozen freshwater is not easily accessible for direct human use. This means that only a tiny fraction of Earth's total water - less than 1% - is available as liquid freshwater suitable for drinking, cooking, farming, and other essential human activities. This scarcity makes freshwater an extremely precious and valuable resource that must be conserved and protected.

In simple words: Most water is salty ocean water. Only a little is freshwater, and much of that is frozen in ice. Very little is available to use.

Exam Tip: Use percentages to support your answer - mention the 97% salt water, 3% freshwater, and the fact that most freshwater is frozen.

What is the water cycle? Explain its steps.

Answer: The water cycle is the continuous process by which water moves from Earth's surface to the atmosphere and back again, repeating endlessly.

Step 1 - Evaporation: The sun heats water in oceans, rivers, lakes, and other water bodies. This heat causes the water to change into water vapour (a gas) and rise into the atmosphere. This process is called evaporation.

Step 2 - Condensation: As water vapour rises higher in the atmosphere, it encounters colder air. The cold causes the invisible water vapour to cool and change back into tiny visible water droplets. These droplets collect together to form clouds in the sky. This process is called condensation.

Step 3 - Precipitation: When clouds become heavy with water droplets, they cannot hold all the water anymore. The water falls back to Earth in the form of rain, snow, or hail. This falling of water is called precipitation.

Step 4 - Collection: The water that falls as precipitation collects in rivers, lakes, ponds, and oceans. Some water also soaks into the ground and becomes groundwater. From these collection points, the cycle begins again as the sun heats the water once more.

In simple words: Sun heats water, it rises as vapour, cools into clouds, falls as rain, and collects in water bodies to start again.

Exam Tip: Name all four steps clearly and explain what happens at each stage, showing how the cycle repeats continuously.

How does a river flow and what decides its direction?

Answer: Rivers begin their journey from high-altitude locations such as mountains or highland regions where water sources originate. From these high points, water naturally flows downward due to the force of gravity, which pulls everything toward lower ground. The shape and slope of the land (called topography) determines which path the river will take as it flows downhill. Rivers follow the contours and depressions in the landscape, curving around obstacles and changing direction based on the terrain. Depending on the slope and direction of the land, some rivers flow eastward toward the Bay of Bengal, while others flow westward toward the Arabian Sea or other seas. For example, the Ganga River flows eastward, while the Narmada River flows westward. The steepness of slopes affects water speed - steeper slopes cause faster flow, while gentler slopes slow the river down. Rivers may split into smaller streams or slow down in flat areas where the land levels out.

In simple words: Rivers start in mountains and flow downhill because of gravity. The shape of the land decides which way they go.

Exam Tip: Explain gravity's role, the influence of land shape, and give examples of rivers that flow in different directions.

What happens to rainwater after it falls on the ground?

Answer: When rain falls on the ground, the water follows several different paths depending on the type of surface and soil conditions.

Some rainwater flows along the surface toward rivers, streams, lakes, and ponds, collecting in these water bodies. This surface flow follows the slope and shape of the land, just like the mustard seed activity demonstrated.

Some rainwater is absorbed directly by soil particles in a process called infiltration or seepage. This water moves downward through the tiny spaces between soil particles and rock layers, traveling deeper and deeper into the ground.

The water that seeps deep underground eventually becomes groundwater, accumulating in layers of soil and rock beneath the surface. This groundwater is later accessed by people using wells, borewells, and handpumps for drinking and other uses.

However, in cities where roads and buildings are made of cement and concrete, rainwater cannot easily soak into the impermeable ground. Instead, the water runs off into drains or puddles, either getting wasted or causing waterlogging and flooding problems.

In natural areas such as forests and villages with open soil and vegetation, rainwater readily soaks into the ground, effectively recharging groundwater supplies and maintaining the water table.

In simple words: Rainwater flows into rivers, soaks into soil to become groundwater, or runs off in cities with cement.

Exam Tip: Describe multiple pathways of rainwater - surface flow, infiltration, groundwater formation - and contrast natural vs. urban conditions.

What are the differences between animals on land and animals in water?

Answer: Land animals and aquatic animals have evolved different body structures and features suited to their specific environments. Land animals breathe using lungs that extract oxygen from air, while aquatic animals use gills that extract oxygen directly from water. Land animals move around using legs or feet to walk, run, or climb on solid ground, whereas water animals use fins or body movements to swim and navigate through water. The skin or body covering differs between the two - land animals typically have fur or skin for protection, while water animals often have scales that provide protection in their aquatic environment. Their habitats are also completely different - land animals make homes in burrows, nests, and forests on the ground, while water animals live permanently in ponds, rivers, lakes, and ocean waters. These differences show how animals adapt perfectly to the environment they live in.

In simple words: Land animals breathe air, walk with legs, have fur, and live on ground. Water animals breathe through water, swim with fins, have scales, and live in water.

Exam Tip: Compare at least four key features - breathing method, movement, body covering, and habitat - to show clear differences between land and water animals.

What are some common aquatic plants and their features?

Answer:
Lotus and Water Lily: These plants have roots that grow in the pond or lake bed at the bottom. Their flowers and leaves float on the water surface where they can get sunlight. These plants have a special waxy coating on their leaves that keeps them waterproof and prevents water from soaking into the plant tissue.

Water Hyacinth: This plant floats freely on the water surface without being attached to the bottom. It spreads very quickly across water bodies and covers large areas. Water hyacinth does not need soil to grow since it floats and gets nutrients from the water.

Reeds: These plants grow along the edges of ponds and water bodies. They are tall and have a grass-like appearance, similar to the grass we see on land. Reeds provide important habitats for water birds and insects.

Hydrilla: This aquatic plant grows completely underwater and never rises above the water surface. It plays an important role in maintaining the water ecosystem by helping to oxygenate the water, providing oxygen that fish and other aquatic life need to survive.

In simple words: Lotus has roots at the bottom and leaves floating on top. Water hyacinth floats freely. Reeds grow at edges. Hydrilla stays underwater.

Exam Tip: Describe the key characteristics of each plant - rooting method, location in water, and special features that help them survive.

How can we help in groundwater recharge?

Answer: There are several important actions individuals and communities can take to help recharge groundwater supplies. First, we should avoid cementing over all open spaces and instead maintain natural soil areas where water can penetrate. Installing soak pits in houses and schools allows rainwater to soak slowly into the ground rather than running off as waste. Planting more trees and creating green areas with grass provides vegetation that helps water absorption. Rainwater harvesting systems should be set up to capture and store water from roofs during rainfall for later use. We should also maintain cleanliness of ponds, lakes, and rivers by keeping them free from garbage and blockages so they can function properly. When groundwater is recharged naturally through these methods, underground water supplies remain healthy and available for wells and handpumps. These conservation practices are especially important in cities where natural groundwater recharge is reduced due to cement and concrete surfaces.

In simple words: Keep soil open for water to soak, plant trees, build rainwater collection systems, and keep water bodies clean.

Exam Tip: List specific actions - avoiding cementation, using soak pits, planting trees, rainwater harvesting, and maintaining clean water bodies.

What is the role of the sun in the water cycle?

Answer: The sun plays a central and essential role as the driving force of the water cycle. The sun's heat warms water in rivers, lakes, oceans, and other water bodies, providing the energy needed for evaporation to occur. As water is heated, it changes from its liquid state into water vapour and rises into the atmosphere. The sun's energy also heats the air in the upper atmosphere, but this cooler air temperature causes the water vapour to cool and condense into clouds. Once clouds form, the sun continues to influence the cycle by driving wind patterns and air circulation. Without the sun's continuous supply of heat energy, water would not evaporate from the oceans and water bodies, clouds would not form, and rain would not fall back to Earth. Essentially, the sun starts and powers the entire water cycle again and again. The sun is the primary energy source that keeps water continuously moving and cycling through all parts of Earth's environment.

In simple words: The sun heats water, makes it rise as vapour, and starts the entire water cycle.

Exam Tip: Emphasize that the sun provides the energy for evaporation and drives the entire water cycle without which there would be no water movement.

How is the journey of a river important for life around it?

Answer: Rivers are vital lifelines for all living beings in the regions they flow through. Rivers provide fresh drinking water to millions of people, animals, and plants along their banks. Farmers depend on river water for irrigation to grow crops and feed their families. People use river water for bathing, cooking, washing, and maintaining cleanliness and health. Rivers support incredibly diverse ecosystems - they are home to fish, birds, insects, and plants that depend on river water for survival. The nutrient-rich soil along river banks is constantly replenished by seasonal flooding, making it extremely fertile for agriculture. This natural fertility helps crops grow well without requiring as many artificial fertilizers. Rivers carry minerals and nutrients in their water that get deposited in fields during irrigation, improving soil quality. Beyond practical benefits, rivers hold deep cultural and spiritual importance in India and many other countries, featuring prominently in religious practices and traditions. Rivers also help recharge groundwater supplies as water seeps from the riverbed into underground layers. The journey of water through rivers creates a complete ecosystem where forests, animals, and human communities flourish together, showing how water is truly the foundation connecting all life.

In simple words: Rivers provide water to drink and for farming, support many living things, and are important to our culture.

Exam Tip: Mention multiple roles - drinking water supply, irrigation for farming, ecosystem support, nutrient cycling, cultural importance, and groundwater recharge.

What does Class 5 EVS Chapter 1 teach us about the availability of freshwater on Earth?

Answer: This chapter teaches a critical understanding about Earth's freshwater availability that challenges our common assumptions. Although our planet appears to have vast amounts of water - with oceans covering most of the surface - the reality is very different for freshwater suitable for human use. The chapter emphasizes that only a very small percentage of Earth's total water is freshwater. Approximately 97% of all water on Earth exists in oceans and contains salt, making it unsuitable for drinking or farming. Out of the remaining 3% that is freshwater, a large portion is frozen permanently in glaciers and polar ice caps in extremely cold regions, remaining inaccessible for direct human use. This leaves only a tiny fraction - less than 1% of Earth's total water - available as usable freshwater in liquid form through rivers, ponds, lakes, and groundwater sources. To help students visualize this scarcity, the chapter uses a simple but powerful comparison: if all of Earth's water were poured into a glass, only about one teaspoon would be usable freshwater. This comparison dramatically illustrates how precious and limited our freshwater supply actually is. The chapter encourages children to respect water as an irreplaceable life-supporting resource and emphasizes the critical importance of conserving and protecting freshwater for our survival and the survival of all life on Earth.

In simple words: Very little of Earth's water is freshwater we can use. Most is salty ocean water or frozen ice. We must save water.

Exam Tip: Use the glass and teaspoon analogy to explain freshwater scarcity, mention the percentages, and emphasize conservation importance.