Our Home Earth A Unique Life Sustaining Planet Class 8 MCQ
hardOur Home Earth A Unique Life Sustaining Planet Class 8 MCQ
Our Home Earth A Unique Life Sustaining Planet Class 8 MCQ
Question 1.
What is the primary reason Earth is considered a unique life-sustaining planet?
(a) Its size
(b) Its distance from the Sun
(c) The presence of liquid water
(d) Its atmosphere
Answer:
(c) The presence of liquid water
Question 2.
What zone is referred to as the 'Goldilocks zone'?
(a) The area where only gas giants exist
(b) The distance from the Sun where conditions are just right for liquid water
(c) The region of space where no planets can exist
(d) The area around the Earth that is affected by gravity
Answer:
(b) The distance from the Sun where conditions are just right for liquid water
Question 3.
If Earth's magnetic field were to disappear, which of the following problems could arise?
(a) Increased solar radiation exposure
(b) Decreased temperatures globally
(c) Increased rainfall
(d) More stable weather patterns
Answer:
(a) Increased solar radiation exposure
Question 4.
Which of the following is NOT a factor that makes Earth habitable?
(a) The presence of an atmosphere
(b) The availability of liquid water
(c) The presence of large land masses
(d) The distance from the Sun
Answer:
(c) The presence of large land masses
Question 5.
What could be a consequence of a village experiencing increasing temperatures and unpredictable rainfall?
(a) Improved crop yields
(b) Increased biodiversity
(c) Water scarcity
(d) More stable weather patterns
Answer:
(c) Water scarcity
Case Study
I. The unique crust of Earth
The Earth's crust is remarkably thin compared to the planet's overall size, akin to the skin of an apple. This delicate layer is where all life exists, hosting diverse ecosystems. The crust's composition, rich in minerals and nutrients, supports plant growth, which in turn sustains animal life, making it essential for the planet's biodiversity.
Question 1.
What is the Earth's crust compared to in terms of thickness?
(a) The surface of a mountain
(b) The skin of an apple
(c) The depth of the ocean
(d) The height of a tree
Answer:
(b) The skin of an apple
Question 2.
Which of the following is NOT a function of the Earth's crust?
(a) Supporting plant growth
(b) Hosting diverse ecosystems
(c) Generating energy from the Sun
(d) Providing minerals and nutrients
Answer:
(c) Generating energy from the Sun
Question 3.
The Earth's crust is a very thin layer compared to the size of the planet, and it is where all ............ exists, including plants, animals, and humans.
Answer:
life
Question 4.
The crust is rich in ............ and nutrients that are essential for the growth of plants, which in turn support various forms of animal life.
Answer: minerals
Question 5.
The Earth's crust is the thickest layer of the Earth, making it the most significant for sustaining life. (True/False)
Answer:
False
II. The Greenhouse Effect and Temperature Regulation
Earth's atmosphere plays a crucial role in maintaining a stable climate through the greenhouse effect. Gases like carbon dioxide trap heat, preventing extreme temperature fluctuations. This regulation allows water to exist in liquid form, essential for all known life. Unlike Venus, where the greenhouse effect leads to extreme heat, Earth strikes a perfect balance.
Question 1.
What is the primary gas responsible for the greenhouse effect on Earth?
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) Methane
Answer:
(c) Carbon dioxide
Question 2.
Which of the following statements best describes the greenhouse effect?
(a) It allows all heat to escape into space.
(b) It traps heat in the atmosphere, preventing extreme temperature fluctuations.
(c) It cools the planet by reflecting sunlight.
(d) It is only beneficial for plant growth in greenhouses.
Answer:
(b) It traps heat in the atmosphere, preventing extreme temperature fluctuations.
Question 3.
The region around a star where conditions are just right for liquid water to exist is known as the ............ zone.
Answer:
habitable
Question 4.
The greenhouse effect is essential for maintaining a stable climate on Earth, allowing water to remain in ............ form.
Answer:
liquid
Question 5.
The greenhouse effect on Venus is less intense than on Earth, making it a more suitable planet for life. (True/False)
Answer:
False