Class 7 Social Science Chapter 1 Important Question Answers - Environment

Q1. Define natural environment. What are its domains?

Ans: Natural Environment: The natural environment includes all objects created by nature, encompassing both physical and ecological elements. It consists of:

• Biotic factors: living organisms, such as plants and animals.
• Abiotic factors: non-living components like land, water, and air.

The main domains of the natural environment are:

• Lithosphere: the Earth's land and soil.
• Hydrosphere: all water bodies, including oceans and lakes.
• Atmosphere: the layer of gases surrounding the planet.
• Biosphere: the global sum of all ecosystems.

Q2. Why is the environment changing? 

Ans: The environment is changing due to our increasing needs. As these needs grow, we often modify or even destroy our natural surroundings.

• Human activities are a major factor in environmental change.
• Deforestation, urbanisation, and pollution contribute significantly.
• Our demand for resources leads to habitat loss and climate change.
• Efforts to conserve and protect the environment are essential.

Q3. Why is the hydrosphere essential for all living organisms? 

Ans: The hydrosphere is crucial for all living organisms for several reasons:

• Source of Water: It includes rivers, lakes, seas, and oceans, providing essential water.
• Survival: Water is vital for hydration, which is necessary for life.
• Nutrient Transport: It helps transport nutrients throughout the body.
• Temperature Regulation: Water plays a key role in maintaining body temperature.
• Overall Functioning: It supports various bodily functions essential for health.

Q4. How does the atmosphere protect us? 

Ans: The atmosphere, a thin layer of air surrounding the Earth, provides essential protection in several ways:

• Blocks harmful radiation: It absorbs and scatters ultraviolet (UV) rays from the sun, reducing the risk of skin cancer and other health issues.
• Regulates temperature: The atmosphere helps to maintain a stable climate by trapping heat, preventing extreme temperatures.
• Supports life: It contains vital gases, such as oxygen and carbon dioxide, necessary for living organisms.
• Protects from meteoroids: Most meteoroids burn up upon entering the atmosphere, preventing them from hitting the Earth's surface.

Q5. How do plants and animals depend on each other? 

Ans: Plants and animals depend on each other for several important reasons:

• Food: Animals eat plants for nutrition, while some plants rely on animals for nutrients from their waste.
• Shelter: Many animals use plants for protection and habitat.
• Pollination: Animals, especially insects, help in the reproduction of plants by transferring pollen.
• Gas exchange: Plants produce oxygen during photosynthesis, which animals need to breathe, while animals produce carbon dioxide that plants use.

Q6. How have humans modified their environment over time? 

Ans: Humans have modified their environment through various significant activities:

• Agriculture: Cultivating land for food production.
• Domestication of animals: Breeding animals for companionship and labour.
• Invention of tools: Developing tools to enhance productivity.
• Industrialisation: Establishing factories and urban areas, leading to large-scale environmental changes.

Q7. When is World Environment Day celebrated? 

Ans: World Environment Day is celebrated on June 5th every year.

Q8. How can individuals contribute to protecting the environment?

Ans: Individuals can contribute to protecting the environment in several effective ways:

• Conserve energy: Switch off lights and appliances when not in use.
• Reduce water usage: Fix leaks and use water-saving fixtures.
• Recycle: Sort and recycle materials like paper, glass, and plastics.
• Plant trees: Participate in local tree planting initiatives.
• Use public transportation: Opt for buses, trains, or cycling instead of driving.
• Support eco-friendly products: Choose sustainable items and practices.