Textbook Solutions: Our Environment | Footprints Class 7: Book Solutions, Notes & Worksheets PDF Download

I. Multiple Choice

Q1.
Ans: (a)

Q2.
Ans: (b)

Q3.
Ans: (a)

Q4.
Ans: (a)

Q5.
Ans: (c)

Q6.
Ans: (b)

Q7.
Ans: (b)

Q8.
Ans: (b)

Q9.
Ans:  (c)

Q10.
Ans: (c)

II. Short Answers

Q1.
Ans: Environment refers to the surroundings within which an organism exists.

Q2.
Ans: The two components of the environment are the natural environment and the human-made environment.

Q3.
Ans: The biosphere is the global ecosystem, comprising all living organisms and their physical environment.

Q4.
Ans: An ecosystem is a natural unit that consists of non-living and living elements interacting with each other in a specific area.

Q5.
Ans: Global warming is caused by an increase in the amount of carbon dioxide in the air, primarily due to human activities.

III. Brief Answers

Q1.
Ans: The natural environment comprises living and non-living things that occur naturally, while the artificial environment consists of elements developed as a result of interaction between humans and nature.

Q2.
Ans: Global ecosystems refer to habitats such as forests, deserts, etc., within the biosphere, while regional ecosystems are specific communities within these habitats.

Q3.
Ans: Human beings need to work towards sustainable development to ensure that the present requirements do not compromise the ability of future generations to meet their basic needs.

Q4.
Ans: Autotrophs can prepare their own food, while heterotrophs depend on other organisms for food.

Q5.
Ans: We can create a sustainable society by checking population growth, using renewable sources of energy, practicing sensible resource use, and recycling waste.

IV. Detailed Answers

Q1.
Ans: The abiotic environment comprises the lithosphere (earth's crust), hydrosphere (water bodies), and atmosphere (air and gases).

Q2.
Ans: All living organisms within the biosphere are interdependent because they rely on each other for survival through food chains and webs, and they also interact with the abiotic environment.

Q3.
Ans: Global warming is the rising average temperature of the Earth's atmosphere and oceans, primarily caused by the increase in carbon dioxide from human activities like transportation and industrial processes.

Q4.
Ans: The human environment includes human beings and their activities, which have transformed the environment to meet their needs, leading to urbanization, overpopulation, and environmental degradation.

Q5.
Ans: Human activities have accelerated environmental degradation through unsustainable practices like clearing forests, overexploitation of resources, and pollution.