Grade 5 Q&A: Chapter 18: The Environment and Us

Concept Questions

Q1: What is 'biodiversity'?

Answer: The variety we see in all the living things that belong to a particular area is called the 'biodiversity' of that place.

Q2: What is the 'environment'?

Answer: The surroundings and the conditions in those surroundings which affect the life of the organisms there, are together known as their environment. It includes components like sunlight, air, water, soil, plants, and animals.

Q3: What does Environmental Science study?

Answer: Environmental Science studies the interactions between living and non-living things, and how they are dependent on each other.

Q4: What is a 'food chain'?

Answer: A food chain is a sequence where each component is food for the next one, showing how living things are connected through their eating habits. For example, grasshoppers eat grass, and birds eat grasshoppers.

Q5: What is a 'food web'?

Answer: A food web is formed when one living thing is a part of a number of food chains, creating an interlinking network of several food chains in nature.

Q6: Why are plants considered the most important food in food chains?

Answer: Plants are the main support of every food chain because they make their own food in the presence of sunlight using water and carbon dioxide from the air. All other living things directly or indirectly depend on plants for food.

Q7: What is 'deforestation'?

Answer: Deforestation is the cutting down of forests on a large scale to make space for agriculture, housing, industry, roads, and railways.

Q8: What are the main reasons for deforestation?

Answer: Deforestation occurs to create open spaces for agriculture, housing, industry, and for building roads and railways, to meet the needs of a growing population.

Q9: How does deforestation affect biodiversity?

Answer: If forests are reduced due to deforestation, the biodiversity is also depleted, as many types of plants and animals lose their habitat and food sources.

Q10: What is 'pollution'?

Answer: Pollution occurs when waste water is let into water bodies without processing, or when poisonous gases and smoke are released into the air from burning fuels and industries, leading to the degradation of air, water, and soil.

Q11: Name two poisonous gases released into the air from burning fuels in vehicles.

Answer: Carbon monoxide, nitrogen dioxide, and sulphur dioxide are poisonous gases released into the air from burning fuels in vehicles.

Q12: What happens when the proportion of carbon dioxide in the air rises continuously?

Answer: When the proportion of carbon dioxide in the air rises continuously, it leads to a rise in temperature across the world.

Q13: Why is it necessary to maintain environmental balance?

Answer: It is necessary to maintain environmental balance because if one factor of the environment is damaged, its relationships with other factors also get affected, threatening the existence of living things and potentially causing the collapse of nature's balance.

Q14: Name two global efforts being made for the protection of the environment.

Answer: Global efforts include implementing international projects to maintain natural balance, enacting laws to prevent pollution of air, water, and soil, and raising awareness about environmental threats.

Q15: What is a 'biodiversity park'?

Answer: A biodiversity park is an area reserved for the purpose of protecting and conserving the biodiversity of a region, where biodiversity is both preserved and studied.

Q16: What is a 'national park'? Give an example.

Answer: National parks are areas reserved for the protection and conservation of wildlife. An example is the Kaziranga National Park or the Tadoba National Park.

Q17: What is a 'sanctuary'? Give an example.

Answer: A sanctuary is a certain forest area reserved for the protection and conservation of a particular animal or plant. An example is the Radhanagari Sanctuary for bisons or the Maldhok (Great Indian Bustard) sanctuary at Nannaj.

Q18: What is a 'Devrai'?

Answer: A Devrai is a traditional sacred grove, believed to be a jungle reserved for god, where no tree or plant is ever cut, thus preserving the trees and providing shelter to plants and animals.

Application-Based Questions

Q19: If forests are cleared on a large scale, will water and food sources for living things grow or dwindle? Why?

Answer: If forests are cleared on a large scale, water and food sources for living things will **dwindle**. Forests are crucial for the water cycle and provide food and shelter. Deforestation leads to less rainfall, soil erosion, and loss of plant life, directly reducing available water and food.

Q20: If forests are cleared on a large scale, will living things look for shelters elsewhere or stay on? Why?

Answer: If forests are cleared on a large scale, living things will **look for shelters elsewhere**. Forests are their natural habitat and provide all their needs. Without trees for nests, dens, and food, animals are forced to migrate to find new homes and sustenance, often leading to conflicts with human settlements or other wildlife.

Q21: If a dam is built at a particular place, what changes will be seen in the environment?

Answer: If a dam is built, several changes will be seen: * **Submergence:** Land upstream will be submerged, displacing plants, animals, and human settlements. * **Water Availability:** Water availability downstream might change, affecting agriculture and ecosystems. * **Biodiversity Loss:** The original biodiversity of the submerged area will be lost. * **New Ecosystem:** A new aquatic ecosystem will form in the reservoir. * **Microclimate:** The local climate might change due to the large water body.

Q22: You see a food chain: Grass -> Grasshopper -> (Missing Link) -> Bird. What picture should be in the blank space? What effect will it have on the grasshopper and the bird if this living thing really died out?

Answer: The missing link should be a **frog** or a **lizard** or any other small animal that eats grasshoppers and is eaten by birds. * **Effect on Grasshopper:** The number of grasshoppers would likely **increase** significantly because their predator (the missing link) is gone. * **Effect on Bird:** The bird's food source would be severely **reduced**, as the missing link is a primary food for the bird. This could lead to a decline in the bird population or force them to find new food sources.

Q23: Why is it important to raise the awareness of people all over the world about the threat to environmental balance?

Answer: It is important to raise global awareness because environmental problems like pollution and climate change are **global issues** that affect everyone, regardless of borders. Collective action and understanding from people worldwide are necessary to implement effective solutions, change harmful practices, and ensure the long-term sustainability of the planet for all living things.

Q24: How much stock of necessary things like water, food, and clothes should we keep with us? Discuss.

Answer: We should keep a **reasonable and sustainable stock** of necessary things. * **Water:** Enough for daily needs, plus a small emergency reserve (e.g., 2-3 days' supply). Excessive storage can lead to wastage or deprivation for others. * **Food:** Enough for immediate consumption and a short-term buffer (e.g., a week's supply of non-perishables). Over-stocking leads to spoilage and contributes to food waste. * **Clothes:** Enough for different seasons and occasions, but not excessive. The chapter emphasizes that "wanting things when we do not need them is simply desire, not necessity," promoting mindful consumption to reduce environmental strain from production and disposal.

Higher-Order Thinking Questions

Q25: "Living and non-living things are dependent on each other. There is a lot of give and take or interaction between them." Elaborate on this statement with examples from the environment.

Answer: This statement highlights the fundamental interconnectedness of ecosystems. Living things depend on non-living components: plants need sunlight, water, and soil for growth; animals need air to breathe and water to drink. Conversely, living things also influence non-living components: plants release oxygen into the air, their roots break down rocks to form soil, and decomposition of dead organisms enriches the soil. This constant "give and take" maintains the environmental balance, where changes in one affect the other, illustrating a complex web of interactions.

Q26: "If one of the links in a chain becomes extinct, can the food chain last?" Justify your answer.

Answer: No, if one of the links in a simple food chain becomes extinct, the food chain **cannot last** in its original form. The extinction of a link means that the organisms that feed on it will lose their food source, and their numbers will decline or they will have to find new food. Similarly, the organisms that were eaten by the extinct link will experience an increase in their population due to the absence of their predator, disrupting the balance of the entire chain. For example, if grasshoppers become extinct, birds that rely solely on them for food will suffer.

Q27: The chapter mentions that "The balance between the cycles of the various gases in the atmosphere, the water cycle and food chains has been maintained for thousands of years." What does this imply about the natural resilience of the environment and the impact of recent human activities?

Answer: This implies that the environment has a remarkable **natural resilience** and a self-regulating capacity, having maintained complex cycles and food chains for millennia. However, the phrase "maintained for thousands of years" subtly contrasts with the rapid changes seen recently due to human activities. It suggests that while nature can balance itself over long periods, the current pace and scale of human intervention (deforestation, pollution, excessive resource use) are overwhelming this natural capacity, leading to a much faster rate of environmental degradation and extinctions, posing an unprecedented threat to this long-standing balance.

Q28: Why is it stated that "Our earth is an invaluable planet" and that its "degradation... will be a threat to the existence of life itself"? Connect this to the concept of environmental balance.

Answer: The earth is "invaluable" because, as the chapter mentions, space scientists haven't found any other planet with life. It possesses the unique conditions (water, air, suitable temperature, and the intricate balance of its spheres) necessary to support diverse living things. Its "degradation" (pollution, deforestation) directly threatens this delicate **environmental balance**. If this balance is disturbed, the life-sustaining systems (like oxygen and water cycles, food chains) will collapse, making the planet uninhabitable for many species, including humans, thus posing a threat to the very existence of life.

Q29: How can individuals contribute to maintaining environmental balance by practicing "using our means frugally and recycling used articles"?

Answer: Individuals can significantly contribute by practicing frugality and recycling. "Using our means frugally" means consuming less and avoiding unnecessary desires (e.g., not buying excessive clothes), which reduces the demand for natural resources and energy-intensive production. "Recycling used articles" means giving materials a new life, reducing the need to extract new raw materials and minimizing waste that pollutes the environment. Both practices lessen the human footprint on nature, reduce pollution, and conserve resources, directly supporting the maintenance of environmental balance.

References

1. Maharashtra State Board Environmental Studies (Part One) Standard Five Textbook (2015 Edition) - Chapter 18: The Environment and Us, pages 89-92.
2. Maharashtra State Board 5th Standard Environmental Studies Syllabus.
3. Balbharati Environmental Studies Part 1 Textbook.