Chapter 13 of Class 8 Science Our Home: Earth, a Unique Life Sustaining Planet has details about why Earth is a unique planet that can support and sustain life. It contains concepts that shows how air, water, soil, reproduction, and natural balance keep life going, and how climate change, pollution, and biodiversity loss threaten our planet.
We have 35 MCQs and 2 match-the-following question for this chapter below. It will help you revise important concepts. Some important topics covered are magnetic field, hydrosphere, geosphere, biosphere, reproduction, vegetative propagation, sexual reproduction, variation etc.
Have a look at Class 8 Science MCQ Questions and Answers.
Our Home: Earth, a Unique Life Sustaining Planet Class 8 Science Chapter 13 MCQ Online Test Questions and Answers
Question 1. Earth is considered a unique planet mainly because it:
a) Is the largest planet in the solar system
b) Is the only known planet where life exists and thrives
c) Is the closest planet to the Sun
d) Has no atmosphere
Answer:
b) Is the only known planet where life exists and thrives
Question 2. The thin outer layer of Earth where all life exists is compared in the chapter to:
a) The core of a seed
b) The shell of an egg
c) The skin of an apple
d) The peel of a banana
Answer:
c) The skin of an apple
Question 3. Earth looks blue from space mainly because:
a) Its atmosphere is blue in colour
b) Most of its surface is covered with water
c) It reflects only blue sunlight
d) Its rocks are mostly blue
Answer:
b) Most of its surface is covered with water
Question 4. The range of distance from a star where water can remain liquid is called the:
a) Ozone zone
b) Habitable zone
c) Magnetic zone
d) Radiation belt
Answer:
b) Habitable zone
Question 5. The habitable zone is also called the:
a) Green zone
b) Blue zone
c) Goldilocks zone
d) Solar zone
Answer:
c) Goldilocks zone
Question 6. Earth can support life mainly because it is at the right distance from the Sun where:
a) Water can remain mostly in liquid form
b) All water becomes steam
c) The atmosphere freezes completely
d) There is no radiation from the Sun
Answer:
a) Water can remain mostly in liquid form
Question 7. If Earth were much closer to the Sun, most of its water would:
a) Freeze
b) Evaporate
c) Turn into rocks
d) Become oxygen
Answer:
b) Evaporate
Question 8. If Earth were much farther from the Sun, most of its water would:
a) Boil away
b) Turn into soil
c) Freeze
d) Become carbon dioxide
Answer:
c) Freeze
Question 9. Venus is hotter than Mercury mainly because Venus has:
a) No atmosphere
b) A thick atmosphere that traps heat
c) More oceans
d) Stronger magnetic field
Answer:
b) A thick atmosphere that traps heat
Question 10. The greenhouse effect on Earth helps to:
a) Remove all heat from the atmosphere
b) Keep Earth warm enough for life
c) Block all sunlight from reaching Earth
d) Eliminate carbon dioxide completely
Answer:
b) Keep Earth warm enough for life
Question 11. The greenhouse effect on Venus and Earth is mainly caused by gases like:
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer:
c) Carbon dioxide
Question 12. Earth’s nearly circular orbit helps life by:
a) Preventing sunlight from reaching Earth
b) Keeping sunlight and heat nearly steady through the year
c) Making Earth the coldest planet
d) Removing all seasonal changes
Answer:
b) Keeping sunlight and heat nearly steady through the year
Question 13. Earth is the right size for life because its gravity is strong enough to:
a) Crush all living beings
b) Hold the atmosphere around it
c) Stop all motion of gases
d) Prevent liquid water from existing
Answer:
b) Hold the atmosphere around it
Question 14. If Earth were much smaller with the same average density, its atmosphere would most likely:
a) Become thicker
b) Escape into space
c) Turn into liquid
d) Become rich in oxygen only
Answer:
b) Escape into space
Question 15. Mercury has no atmosphere mainly because its gravity is not enough to:
a) Reflect sunlight
b) Hold gases around the planet
c) Support oceans
d) Create rocks
Answer:
b) Hold gases around the planet
Question 16. The ozone layer is important because it:
a) Produces rain
b) Blocks harmful ultraviolet rays from the Sun
c) Creates all oxygen in the atmosphere
d) Makes Earth hotter than Venus
Answer:
b) Blocks harmful ultraviolet rays from the Sun
Question 17. Ozone is a form of oxygen made up of:
a) One oxygen atom
b) Two oxygen atoms
c) Three oxygen atoms
d) Four oxygen atoms
Answer:
c) Three oxygen atoms
Question 18. Earth behaves like a giant magnet because of the movement of:
a) Water in the oceans
b) Molten iron in its core
c) Clouds in the atmosphere
d) Soil in the crust
Answer:
b) Molten iron in its core
Question 19. The solar wind consists of:
a) Water vapour from the Sun
b) High-energy particles coming from the Sun
c) Sound waves from the Sun
d) Light reflected by planets
Answer:
b) High-energy particles coming from the Sun
Question 20. Earth’s magnetic field protects life by:
a) Pulling oxygen into the soil
b) Pushing many harmful high-energy particles away
c) Stopping Earth’s rotation
d) Creating rainfall directly
Answer:
b) Pushing many harmful high-energy particles away
Question 21. The atmosphere, hydrosphere, geosphere, and biosphere together help to:
a) Destroy life on Earth
b) Sustain life on Earth
c) Remove all natural resources
d) Stop reproduction in organisms
Answer:
b) Sustain life on Earth
Question 22. The hydrosphere includes:
a) Only oceans
b) Only glaciers
c) All water on Earth
d) Only underground water
Answer:
c) All water on Earth
Question 23. The geosphere consists of the:
a) Air and gases around Earth
b) Solid parts of Earth like rocks, soil, and minerals
c) All living things only
d) Rain and clouds only
Answer:
b) Solid parts of Earth like rocks, soil, and minerals
Question 24. The biosphere includes:
a) Only plants
b) Only animals
c) All living beings and the places where they live
d) Only microorganisms in soil
Answer:
c) All living beings and the places where they live
Question 25. Plants use carbon dioxide, water, and sunlight to prepare food by:
a) Respiration
b) Germination
c) Photosynthesis
d) Fermentation
Answer:
c) Photosynthesis
Question 26. Soil supports plant growth because it contains nutrients such as:
a) Hydrogen and helium
b) Nitrogen and potassium
c) Ozone and methane
d) Carbon dioxide and argon
Answer:
b) Nitrogen and potassium
Question 27. The variety of landforms, rocks, and soils on Earth is called:
a) Biodiversity
b) Geodiversity
c) Atmosphere
d) Hydrology
Answer:
b) Geodiversity
Question 28. Reproduction is essential because it:
a) Stops all changes in organisms
b) Ensures the continuity of life
c) Prevents offspring from resembling parents
d) Eliminates variation completely
Answer:
b) Ensures the continuity of life
Question 29. Genes are best described as:
a) Extra food stored in cells
b) Instruction manuals stored inside cells
c) Waste substances in blood
d) Layers of the atmosphere
Answer:
b) Instruction manuals stored inside cells
Question 30. In asexual reproduction, new individuals are usually:
a) Completely different from the parent
b) Exact copies of the parent
c) Formed by the joining of gametes from two parents
d) Produced only in animals
Answer:
b) Exact copies of the parent
Question 31. Vegetative propagation is a type of asexual reproduction in which a new plant can grow from a:
a) Leaf, stem, or root
b) Flower only
c) Fruit only
d) Seed coat only
Answer:
a) Leaf, stem, or root
Question 32. In sexual reproduction, offspring differ from their parents mainly because they receive genetic material from:
a) Only one parent
b) Two parents
c) Soil and water
d) Atmosphere and sunlight
Answer:
b) Two parents
Question 33. Gametes are special reproductive cells that carry:
a) A double set of genetic material
b) No genetic material
c) Half of the parent’s genetic material
d) Only food for the embryo
Answer:
c) Half of the parent’s genetic material
Question 34. In flowering plants, pollination is the transfer of pollen grains from the anther to the:
a) Sepal
b) Petal
c) Ovule
d) Another flower part containing the female structure
Answer:
d) Another flower part containing the female structure
Question 35. In animals like fish and frogs, fertilisation usually takes place:
a) Inside the egg before it is formed
b) In water outside the body
c) Only inside the mother’s body
d) Only after the embryo is fully formed
Answer:
b) In water outside the body
Question 36. Climate change, biodiversity loss, and pollution together are known as the:
a) Triple atmospheric crisis
b) Triple planetary crisis
c) Global oxygen crisis
d) Geosphere crisis
Answer:
b) Triple planetary crisis
Question 37 – Match the Following
| Column A | Column B |
|---|---|
| 1. Habitable zone | A. Blocks harmful UV rays |
| 2. Ozone layer | B. Region where liquid water can exist |
| 3. Hydrosphere | C. All water on Earth |
| 4. Geosphere | D. Solid parts of Earth like rocks and soil |
| 5. Biosphere | E. All living beings and their living zones |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Habitable zone | B. Region where liquid water can exist |
| 2. Ozone layer | A. Blocks harmful UV rays |
| 3. Hydrosphere | C. All water on Earth |
| 4. Geosphere | D. Solid parts of Earth like rocks and soil |
| 5. Biosphere | E. All living beings and their living zones |
Question 38 – Match the Following
| Column A | Column B |
|---|---|
| 1. Asexual reproduction | A. Mixing of instructions from two parents |
| 2. Sexual reproduction | B. New individuals are exact copies |
| 3. Vegetative propagation | C. New plant grows from stem, root, or leaf |
| 4. Gametes | D. Special reproductive cells with half the genetic material |
| 5. Triple planetary crisis | E. Climate change, biodiversity loss, and pollution |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Asexual reproduction | B. New individuals are exact copies |
| 2. Sexual reproduction | A. Mixing of instructions from two parents |
| 3. Vegetative propagation | C. New plant grows from stem, root, or leaf |
| 4. Gametes | D. Special reproductive cells with half the genetic material |
| 5. Triple planetary crisis | E. Climate change, biodiversity loss, and pollution |
