Science for Grade 7
1 Introduction to Science
1-1 Definition of Science
1-2 Importance of Science in Daily Life
1-3 Scientific Method
1-3 1 Observation
1-3 2 Hypothesis
1-3 3 Experimentation
1-3 4 Analysis
1-3 5 Conclusion
2 Matter and Its Properties
2-1 States of Matter
2-1 1 Solid
2-1 2 Liquid
2-1 3 Gas
2-2 Properties of Matter
2-2 1 Mass
2-2 2 Volume
2-2 3 Density
2-2 4 Solubility
2-3 Changes in Matter
2-3 1 Physical Changes
2-3 2 Chemical Changes
2-4 Mixtures and Solutions
2-4 1 Types of Mixtures
2-4 2 Separation Techniques
3 Force and Motion
3-1 Types of Forces
3-1 1 Gravitational Force
3-1 2 Frictional Force
3-1 3 Magnetic Force
3-1 4 Electrostatic Force
3-2 Motion
3-2 1 Speed and Velocity
3-2 2 Acceleration
3-2 3 Newton's Laws of Motion
3-2 3-1 First Law (Inertia)
3-2 3-2 Second Law (Force and Acceleration)
3-2 3-3 Third Law (Action and Reaction)
4 Energy
4-1 Forms of Energy
4-1 1 Kinetic Energy
4-1 2 Potential Energy
4-1 3 Thermal Energy
4-1 4 Electrical Energy
4-1 5 Light Energy
4-1 6 Sound Energy
4-2 Energy Conversion
4-2 1 Mechanical to Electrical
4-2 2 Chemical to Thermal
4-2 3 Light to Electrical
4-3 Conservation of Energy
5 Heat and Temperature
5-1 Temperature
5-1 1 Measurement of Temperature
5-1 2 Temperature Scales
5-2 Heat Transfer
5-2 1 Conduction
5-2 2 Convection
5-2 3 Radiation
5-3 Effects of Heat
5-3 1 Expansion
5-3 2 Change of State
6 Light and Sound
6-1 Light
6-1 1 Sources of Light
6-1 2 Reflection
6-1 3 Refraction
6-1 4 Lenses and Mirrors
6-2 Sound
6-2 1 Production of Sound
6-2 2 Properties of Sound
6-2 3 Reflection of Sound
6-2 4 Applications of Sound
7 Earth and Space
7-1 Earth's Structure
7-1 1 Crust
7-1 2 Mantle
7-1 3 Core
7-2 Earth's Atmosphere
7-2 1 Layers of the Atmosphere
7-2 2 Weather and Climate
7-3 Solar System
7-3 1 Planets
7-3 2 Sun
7-3 3 Moon
7-4 Space Exploration
7-4 1 Rockets
7-4 2 Satellites
7-4 3 Space Stations
8 Living Organisms and Ecosystems
8-1 Classification of Living Organisms
8-1 1 Kingdoms
8-1 2 Species
8-2 Ecosystems
8-2 1 Components of an Ecosystem
8-2 2 Food Chains and Webs
8-3 Adaptations
8-3 1 Physical Adaptations
8-3 2 Behavioral Adaptations
8-4 Human Impact on Ecosystems
8-4 1 Pollution
8-4 2 Conservation Efforts
9 Health and Nutrition
9-1 Human Body Systems
9-1 1 Circulatory System
9-1 2 Respiratory System
9-1 3 Digestive System
9-1 4 Nervous System
9-2 Nutrition
9-2 1 Essential Nutrients
9-2 2 Balanced Diet
9-3 Diseases and Prevention
9-3 1 Infectious Diseases
9-3 2 Non-infectious Diseases
9-3 3 Hygiene and Prevention
10 Environmental Science
10-1 Natural Resources
10-1 1 Renewable Resources
10-1 2 Non-renewable Resources
10-2 Pollution
10-2 1 Air Pollution
10-2 2 Water Pollution
10-2 3 Soil Pollution
10-3 Sustainable Development
10-3 1 Importance of Sustainability
10-3 2 Sustainable Practices
10-4 Climate Change
10-4 1 Causes of Climate Change
10-4 2 Effects of Climate Change
10-4 3 Mitigation Strategies
8. Living Organisms and Ecosystems Explained

Understanding Living Organisms and Ecosystems

Key Concepts

1. Living Organisms

Living organisms are entities that exhibit characteristics such as growth, reproduction, metabolism, and response to stimuli. They can be classified into various groups based on their characteristics.

2. Classification of Living Organisms

Living organisms are classified into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia. Each kingdom includes organisms with similar characteristics and traits.

3. Ecosystem

An ecosystem is a community of living organisms interacting with each other and their physical environment. It includes both biotic (living) and abiotic (non-living) components.

4. Biotic Components

Biotic components are the living parts of an ecosystem, including producers (plants), consumers (animals), and decomposers (fungi and bacteria).

5. Abiotic Components

Abiotic components are the non-living parts of an ecosystem, such as air, water, soil, sunlight, and temperature. These factors influence the survival and behavior of living organisms.

6. Food Chains and Food Webs

Food chains and food webs represent the flow of energy and nutrients through an ecosystem. A food chain shows a single path of energy transfer, while a food web shows multiple interconnected paths.

7. Ecological Balance

Ecological balance refers to the stable state of an ecosystem where the number of organisms and their interactions with the environment are in equilibrium. Disruptions can lead to imbalances.

8. Human Impact on Ecosystems

Human activities such as deforestation, pollution, and overfishing can significantly impact ecosystems. Understanding these impacts is crucial for sustainable living and environmental conservation.

Explanation of Each Concept

1. Living Organisms

Living organisms exhibit characteristics like growth, reproduction, metabolism, and response to stimuli. For example, plants grow from seeds, reproduce through pollination, and respond to sunlight for photosynthesis.

2. Classification of Living Organisms

The five kingdoms of living organisms include Monera (bacteria), Protista (protozoa), Fungi (mushrooms), Plantae (plants), and Animalia (animals). Each kingdom has unique characteristics, such as bacteria being single-celled and plants having chlorophyll for photosynthesis.

3. Ecosystem

An ecosystem consists of both living and non-living components. For example, a forest ecosystem includes trees (biotic) and sunlight, soil, and water (abiotic). These components interact to create a balanced environment.

4. Biotic Components

Biotic components include producers like plants that create energy through photosynthesis, consumers like animals that eat plants or other animals, and decomposers like fungi and bacteria that break down dead organisms.

5. Abiotic Components

Abiotic components such as air, water, soil, sunlight, and temperature affect the survival and behavior of living organisms. For example, plants need sunlight for photosynthesis, and animals need water for hydration.

6. Food Chains and Food Webs

Food chains show a single path of energy transfer, such as grass → rabbit → fox. Food webs show multiple interconnected paths, such as grass → rabbit → fox and grass → deer → wolf. This complexity highlights the interdependence of organisms.

7. Ecological Balance

Ecological balance is maintained when the number of organisms and their interactions with the environment are stable. For example, a balanced forest ecosystem has a stable population of trees, animals, and decomposers.

8. Human Impact on Ecosystems

Human activities like deforestation, pollution, and overfishing can disrupt ecosystems. For example, deforestation reduces the number of trees, leading to habitat loss for animals and increased carbon dioxide levels.

Examples and Analogies

Example 1: Forest Ecosystem

A forest ecosystem is like a bustling city where trees are the buildings, animals are the residents, and sunlight and water are the utilities. Each component plays a role in maintaining the city's functionality.

Example 2: Food Web in a Pond

A pond ecosystem's food web is like a complex network of roads connecting different neighborhoods. Algae are the primary producers, small fish eat algae, larger fish eat small fish, and birds eat fish. This interconnectedness ensures energy flows through the ecosystem.

Analogy: Ecosystem as a Symphony

Think of an ecosystem as a symphony where each organism is a musician playing a different instrument. When all musicians play in harmony, the symphony is beautiful and balanced. Disruptions, like a musician playing out of tune, can lead to disharmony.