Lakhmir Singh Solutions for Class 10 Biology Chapter 5 Question Answers

Lakhmir Singh Solutions for Class 10 Biology Chapter 5: Lakhmir Singh’s Class 10 Biology Chapter 5: Our Environment focuses on ecosystems, food chains, and environmental issues.

It explains components of an ecosystem, the flow of energy through food chains and food webs, and the 10% Law of energy transfer. 

 The chapter also highlights the impact of human activities, such as pollution and waste disposal, on the environment. Key topics include biodegradable and non-biodegradable substances, ozone layer depletion, and waste management strategies.

The chapter emphasizes sustainable development and the need for conservation to maintain ecological balance. Solutions provide detailed explanations and NCERT-based answers for better understanding.

Lakhmir Singh Solutions for Class 10 Biology Chapter 5 Overview

Lakhmir Singh’s Class 10 Biology Chapter 5: Our Environment explains the structure and functioning of ecosystems, focusing on food chains, food webs, and energy flow.

The 10% Law highlights energy transfer between trophic levels, emphasizing ecological balance. The chapter discusses biodegradable and non-biodegradable waste, pollution, and ozone layer depletion, stressing the impact of human activities. 

 Understanding these concepts is crucial for environmental conservation and sustainable development. The solutions provide detailed NCERT-based answers, aiding students in grasping key concepts and preparing effectively for exams.

Awareness of these topics helps in promoting responsible environmental practices for a healthier planet.

Lakhmir Singh Solutions for Class 10 Biology Chapter 5 PDF

Lakhmir Singh’s Class 10 Biology Chapter 5: Our Environment covers essential topics like ecosystems, food chains, energy flow, pollution, and waste management.

It highlights the importance of sustainable development and environmental conservation. Understanding these concepts helps students develop eco-friendly habits. Below, we have provided a PDF containing detailed solutions to help students grasp key concepts easily and prepare effectively for their exams.

Lakhmir Singh Solutions for Class 10 Biology Chapter 5 PDF

Lakhmir Singh Solutions for Class 10 Biology Chapter 5 Our Environment

1. What is the functional unit of the environment comprising of the living and non-living components called?

Answer

The ecosystem is the functional unit of the environment consisting of living and non-living components.

2. Name two natural ecosystems and two artificial ecosystems.

Answers

The forest ecosystem and the pond ecosystem are two examples of natural ecosystems. Crop fields and aquariums are two examples of artificial ecosystems. 

3. Which one of the following is not a terrestrial ecosystem?
Forest, Grassland, Aquarium, Desert

Answer

An aquarium is not a terrestrial ecosystem.

4. Why are plants called producers?

Answers

Because they employ photosynthesis to make their own food, plants are referred to as producers. 

5. What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants?

Answer

Decomposers are the organisms that break down the complex organic compounds present in dead animals and plants.

6. What are planktons?

Answer

The tiny herbivorous plants and animals present in water are known as plankton.

7. State whether the following statements are true or false :
(a) In biology, human beings are called producers.
(b) Secondary consumers and tertiary consumers are both carnivores.

Answer

(a) False

(b) True

8. Which category of organisms forms the starting point of a food chain?

Answer

Green plants or producers form the starting point of a food chain.

9. Which of the following belongs to the same trophic level?
Goat; Spider; Plants; Hawk; Rat

Answer

Goats and rats belong to the same trophic level.

10. Which of the following belongs to the same trophic level?
Tree; Frog; Snake; Grass; Lizard

Answer

Trees and grass belong to the same trophic level.

11. Write an aquatic food chain.

Answer

Plankton → Fish → Crane →Hawk

12. Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following:
Frogs, Plants, Snakes, Hawk, Insects

Answer

Second trophic level: Insects

Fourth trophic: Snakes

13. What are the various steps of the food chain called?

Answer

The various steps of a food chain are called trophic levels.

14. Construct a food chain comprising the following:
Snakes, Hawk, Rats, Plants

Answer

Plants → Rats  → Snakes   →Hawks

15. Arrange the following in a food chain:
Fish, Algae, Small animals, Big Fish

Answer

Algae→ Small animals → Fish → Big fish

16. Which organisms belong to the third and fourth trophic levels in the food chain comprising the following?
Rats, Plants, Hawk, Snakes

Answer

Third trophic level: Snake

Fourth trophic level: Hawk

17. Which one term in the following includes the others?
Air, flora, fauna, environment, water, sunlight, soil

Answer

The environment is the term that includes air, flora, fauna, water, sunlight and soil.

18. A food chain represents a unidirectional flow of X. What is X?

Answer

X is energy.

19. Fill in the following blanks with suitable words :
(a) Decomposer organisms are _________in their action.
(b) In nature, all green plants are_________ whereas animals are consumers.
(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a _________
(d) The science that deals with the inter-relationships of living things with one another and their environment is called_________
(e) Plastic is a _________material whereas paper is a _________material.

Answer

(a) Decomposer organisms are specific in their action.

(b) In nature, all green plants are producers, whereas animals are consumers.

(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a food chain.

(d) The science that deals with the inter-relationships of living things with one another and their environment is called ecology.

(e) Plastic is a non-biodegradable material, whereas paper is a biodegradable material.

20. Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.

Answers

Producers are organisms that use readily available basic materials, such as carbon dioxide and water, to make their own food. For instance, green plants

Consumers are organisms that rely on food produced by producers. For instance, animals 

21. (a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem?

Answer

(a) Decomposers are microorganisms that convert complex organic molecules found in dead plants and animals as well as their byproducts, including urine and faeces, into simpler substances. Decomposers are bacteria.

(b) Decomposers maintain a clean and fresh environment by breaking down dead plants and animals. 

22. What is meant by a primary consumer, secondary consumer and tertiary consumer? Give one example of each.

Answer

The consumers that feed on the producers that are on plants are called primary consumers. Example: Insects.

The consumers that feed on primary consumers are called secondary consumers. Example: Frogs.

The consumers that feed on secondary consumers are called tertiary consumers. Example: Birds.

Insects →    Frog →     Birds

23. Give an example of a four-step food chain operating in grassland. Name the secondary consumer in this food chain

Grass →Insect → Butterfly → Crow

The secondary consumer in this food chain is the butterfly

24. (a) Define trophic level. Draw the food chain with four trophic levels.
(b) What will happen if we kill all the organisms at one trophic level?

Answer

(a) The various steps in a food chain at which the transfer of food and energy takes place are known as trophic levels.

A food chain with four trophic levels can be shown as follows.

Grass → Insect → Butterfly → Crow

(b) If we kill all the organisms in one trophic level, there will be no food for the organisms of the next trophic level, and this may cause the death of those animals. Also, the organisms of the previous trophic levels may increase in number as there will be no organisms to consume them as food which leads to an imbalance in the ecosystem.

25. What is the difference between the food habits of organisms belonging to the first and the third trophic levels? Give one example of each of the organisms belonging to these two trophic levels.

Answer

Because they are producers, creatures in the first trophic level make their own food. Plants, for instance. Carnivores that rely on herbivores for sustenance are the species in the third trophic level. Lion, for instance 

26. Can the organisms of any trophic level be removed without causing any damage to the ecosystem? Will the impact of removing all the organisms in a trophic level be different for different trophic levels?

Answer

No, it is possible to eradicate species from any trophic level without endangering the environment. The environment would become unbalanced as a result. Indeed, the effects of eliminating every organism in a given trophic level will vary depending on the trophic level.

Since producers constitute the foundation of the food chain at the first tropic level, their removal will prevent creatures from the higher trophic levels from existing. In a similar vein, eliminating species from one level will have an impact on the subsequent level, leading to the extinction of organisms from that level. 

27. Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain?

Answer

If all the lions are removed from the above food chain, the population of deer will increase greatly, as there will be no lion to consume them as food. Then the density of grass will decrease due to overconsumption by a large number of deer.

28. The number of malaria patients in a village increased tremendously when a large number of frogs were exported from the village. What could be the cause for it?

Answer

Because frogs consume the insects that cause malaria, a hamlet's malaria cases skyrocketed after a significant number of frogs were exported from the village. The exportation of frogs has led to a sharp rise in the number of insects that spread malaria. 

29. How does biodegradable waste differ from non-biodegradable waste? Give two examples of non-biodegradable wastes which pollute our environment.

Answer

Biodegradable waste: The waste material that can be easily broken down into non-poisonous substances that can be decomposed and recycled easily is called biodegradable waste. Example: Kitchen waste, paper bits etc.

Non- Biodegradable waste: The waste material that cannot be broken down into non-poisonous substances also that cannot be decomposed and recycled is called non-biodegradable waste. Example: Plastic, polythene bags etc.

30. Which of the following are biodegradable, and which are non-biodegradable?
Glass bottle, Paper, Ballpoint pen refill, Hay, DDT, Wheat, Cake, Wood, Polythene bag, Jute bag, Cotton cloth, Grass, Vegetable peels

Answer

Biodegradable: Paper, hay, wheat, cake, wood, jute bag, cotton cloth, grass, vegetable peels.

Non-biodegradable: Glass bottle, ballpoint pen refill, DDT, polythene bag.

Benefits of Using Lakhmir Singh Solutions for Class 10 Biology Chapter 5 

Concept Clarity – Provides detailed explanations, making it easier to understand topics like ecosystems, energy flow, and pollution.

NCERT-Based Solutions – Follows the CBSE syllabus, ensuring relevance for board exams.

Easy Language – Simplifies complex topics for better comprehension.

Diagrammatic Representation – Includes well-labeled diagrams for visual learning.

Step-by-Step Answers – Helps in structured learning and effective revision.

Boosts Exam Preparation – Covers important questions likely to appear in exams.

Improves Problem-Solving Skills – Enhances analytical thinking with practical examples.

Time-Saving Resource – Provides precise answers, reducing study time.