Photosynthesis is how plants make food using sunlight, water, and carbon dioxide.

• Chlorophyll in leaves captures sunlight.
• Water and CO₂ convert into glucose and oxygen.

Our textbook shows it produces oxygen for animals. Without it, life wouldn’t exist!

The water cycle recycles water through evaporation, condensation, and precipitation.

• Sun heats water → evaporates.
• Clouds form (condensation).
• Rain falls (precipitation).

NCERT shows rivers refill due to rain. Farmers depend on it for crops.

Adaptations help animals live in harsh deserts.

• Camels store fat in humps for energy.
• Rats live underground to avoid heat.

Our textbook mentions kangaroo rats conserve water. Similarly, fennec foxes have big ears to cool down.

Reflection is when light bounces off a surface.

• NCERT experiment: Torchlight on a mirror → angle in = angle out.
• Smooth surfaces reflect better.

Mirrors in cars help drivers see behind. Periscopes use reflection too!

Composting turns waste into nutrient-rich soil.

• Mix kitchen scraps + dry leaves.
• Microbes break it down.

NCERT shows it reduces landfill waste. My school composts to grow plants!

The water cycle is nature's way of recycling water through evaporation, condensation, and precipitation.

• Sun heats water, turning it into vapor (evaporation).
• Vapor cools to form clouds (condensation).
• Clouds release rain/snow (precipitation).

Our textbook shows how farmers rely on rain for crops. Without the cycle, rivers would dry up.

Photosynthesis is how plants make food using sunlight, water, and carbon dioxide.

• Leaves absorb sunlight.
• Water and CO₂ convert into glucose and oxygen.

Our textbook shows a banyan tree making food. Without photosynthesis, animals wouldn’t get oxygen.

Desert animals have special adaptations to survive extreme heat and water scarcity.

• Camels store fat in humps for energy.
• Kangaroo rats get water from food.

Our textbook mentions the desert fox having large ears to cool down. Without adaptations, they couldn’t live there.

Sieving separates smaller particles from larger ones using a sieve.

• Flour is sieved to remove lumps.
• Sand and pebbles are separated this way.

Our textbook shows how tea leaves are filtered. At home, we sieve flour for smooth dough.

An electric circuit is a closed path for current to flow and power devices.

• Battery provides energy.
• Wires carry current to the bulb.

Our textbook shows a torch circuit. Without a closed path, the bulb won’t glow.

Photosynthesis is the process by which green plants make their own food using sunlight, carbon dioxide, and water. Here’s how it works:

1. Chlorophyll, the green pigment in leaves, captures sunlight.
2. The plant takes in carbon dioxide from the air through tiny pores called stomata.
3. Water is absorbed from the soil by the roots and transported to the leaves.
4. Using sunlight, chlorophyll converts carbon dioxide and water into glucose (food) and releases oxygen as a byproduct.

Importance of Chlorophyll and Sunlight:
- Chlorophyll traps sunlight, which provides the energy needed for the process.
- Without sunlight, photosynthesis cannot occur, and plants won’t produce food.

Diagram (Labeled):
(Draw a simple diagram of a leaf showing:
- Sunlight entering the leaf
- Carbon dioxide (CO₂) and water (H₂O) as inputs
- Glucose and oxygen (O₂) as outputs
- Chlorophyll highlighted in green)

The water cycle is the continuous movement of water on Earth through evaporation, condensation, and precipitation. Here’s how it works:

1. Evaporation: The sun heats water in rivers, lakes, and oceans, turning it into water vapor that rises into the air.
2. Condensation: As the vapor cools high in the atmosphere, it forms tiny water droplets, creating clouds.
3. Precipitation: When these droplets become heavy, they fall back to Earth as rain, snow, or hail.

Diagram: (Draw a cycle showing evaporation from water bodies, condensation forming clouds, and precipitation returning water to the ground.)

Why is the water cycle important? It ensures a continuous supply of fresh water for plants, animals, and humans.

The scientific method is a systematic approach used by scientists to investigate and solve problems. It involves the following steps:

• Observation: Noticing a problem or phenomenon (e.g., a plant not growing well).
• Question: Formulating a question (e.g., Why is the plant not growing?).
• Hypothesis: Making an educated guess (e.g., The plant may need more sunlight).
• Experiment: Testing the hypothesis (e.g., Moving the plant to a sunnier spot).
• Analysis: Observing results (e.g., The plant grows better).
• Conclusion: Drawing a conclusion based on evidence.

This method helps in solving problems logically and avoids guesswork. For example, if a student notices their phone battery drains quickly, they can use the scientific method to test if closing background apps saves battery life.

Measurement is crucial in science because it provides precise and reliable data for experiments. Here’s why it matters:

• Consistency: Measurements ensure experiments can be repeated. For example, measuring 50 mL of water for a chemical reaction ensures the same conditions every time.
• Accuracy: Correct measurements lead to valid results. If you measure 10 grams of salt instead of estimating, the experiment’s outcome will be accurate.
• Comparison: Scientists compare results globally. For instance, measuring temperature in degrees Celsius allows everyone to understand the data.

Accurate measurement improves experiments by:
1. Reducing errors caused by guesswork.
2. Ensuring reproducibility of results.
3. Building trust in scientific findings.

For example, in a baking experiment, measuring exact amounts of flour and sugar ensures the cake turns out perfectly every time.

Recycling is the process of converting waste materials into reusable objects to reduce pollution and conserve resources. Its importance includes:

• Reducing landfill waste: Less trash means fewer harmful chemicals leaching into soil and water.
• Saving energy: Recycling aluminum uses 95% less energy than making new aluminum.
• Conserving resources: Reusing paper saves trees, protecting forests and wildlife.

Examples of recyclable materials:

• Paper: Old newspapers can become new notebooks.
• Plastic: Bottles are melted to make new containers.
• Glass: Broken jars are reshaped into new bottles.

Recycling benefits society by creating jobs in recycling industries, reducing pollution-related health risks, and teaching sustainable habits for future generations.

The water cycle is the continuous movement of water on Earth through evaporation, condensation, and precipitation. Here’s how it works:

1. Evaporation: The sun heats water in rivers, lakes, and oceans, turning it into water vapor that rises into the air.
2. Condensation: As the water vapor cools high in the atmosphere, it forms tiny droplets that gather to form clouds.
3. Precipitation: When the clouds become heavy, water falls back to Earth as rain, snow, or hail.

Diagram (Labeled):
(Draw a simple water cycle diagram with:
- Sun heating water (evaporation)
- Clouds forming (condensation)
- Rain falling (precipitation)
- Arrows showing the cycle’s flow)

Importance:
- The water cycle ensures freshwater is available for plants, animals, and humans.
- It helps maintain Earth’s climate balance.

The scientific method is a systematic way of finding answers to questions through observation and experimentation. It involves the following steps:

• Observation: Noticing something interesting, like plants growing taller near a window.
• Question: Why do plants near the window grow better?
• Hypothesis: Maybe plants need sunlight to grow well.
• Experiment: Grow two plants—one near the window (with sunlight) and one in a dark room.
• Analysis: Compare their growth after a week.
• Conclusion: The plant near the window grows better, proving sunlight is important.

This method helps solve everyday problems, like figuring out why a phone battery drains fast by testing different usage patterns.

Recycling is the process of converting waste materials into reusable objects to reduce pollution and save natural resources. Its importance includes:

• Reduces landfill waste: Fewer trash piles mean less soil and water pollution.
• Saves energy: Making products from recycled materials uses less energy than raw materials.
• Conserves resources: Recycling paper saves trees, and recycling metals reduces mining.

Examples of recyclable materials:

• Paper: Newspapers, cardboard
• Plastic: Bottles, containers
• Glass: Jars, bottles
• Metal: Cans, aluminum foil

By recycling, we protect the environment for future generations.

Recycling is the process of converting waste materials into reusable objects to reduce pollution and conserve natural resources. Its importance includes:

• Reducing waste: Less trash ends up in landfills.
• Saving energy: Recycling uses less energy than producing new items (e.g., recycling aluminum saves 95% energy).
• Conserving resources: It reduces the need for raw materials like trees and minerals.

Examples of recyclable materials:

• Paper: Newspapers, notebooks.
• Plastic: Bottles, containers.
• Glass: Jars, bottles.
• Metal: Cans, foil.

By recycling, we protect the environment and ensure a sustainable future. For instance, recycling one ton of paper saves 17 trees!