ICAS Earth and Environmental Science 2 — Questions and Answers
Question 1: Which layer of Earth's atmosphere contains the ozone layer that protects life from harmful ultraviolet radiation?
- Troposphere
- Stratosphere (Correct answer)
- Mesosphere
- Thermosphere
Correct answer: Stratosphere
The ozone layer is located in the stratosphere, approximately 15–35 km above Earth's surface.
Question 2: What process causes rocks to break down into smaller pieces through physical means without changing their chemical composition?
- Chemical weathering
- Erosion
- Mechanical weathering (Correct answer)
- Deposition
Correct answer: Mechanical weathering
Mechanical (physical) weathering breaks rocks into smaller pieces without altering their chemical makeup, such as through freeze-thaw cycles.
Question 3: Which type of rock forms when magma cools and solidifies underground?
- Sedimentary
- Metamorphic
- Extrusive igneous
- Intrusive igneous (Correct answer)
Correct answer: Intrusive igneous
Intrusive igneous rocks like granite form when magma solidifies slowly beneath Earth's surface.
Question 4: What is the main driver of ocean surface currents?
- Differences in water temperature only
- Tidal forces from the Moon
- Wind blowing across the ocean surface (Correct answer)
- Underwater earthquakes
Correct answer: Wind blowing across the ocean surface
Surface ocean currents are primarily driven by global wind patterns that push water in consistent directions.
Question 5: Which greenhouse gas is produced in the largest quantity by human agricultural practices, particularly from livestock and rice paddies?
- Carbon dioxide (CO₂)
- Methane (CH₄) (Correct answer)
- Nitrous oxide (N₂O)
- Water vapor (H₂O)
Correct answer: Methane (CH₄)
Methane is released in large amounts from cattle digestion and flooded rice paddies, making agriculture a major source.
Question 6: What term describes the gradual movement of continents over millions of years due to the motion of tectonic plates?
- Seafloor spreading
- Continental drift (Correct answer)
- Subduction
- Isostasy
Correct answer: Continental drift
Continental drift is the theory that Earth's continents have shifted position over geological time, originally proposed by Alfred Wegener.
Question 7: Which of the following best describes a renewable resource?
- Coal formed over millions of years
- Natural gas trapped in shale
- Solar energy that is continuously replenished (Correct answer)
- Uranium used in nuclear reactors
Correct answer: Solar energy that is continuously replenished
Solar energy is a renewable resource because it is continuously supplied by the Sun and will not run out on human timescales.
ICAS Earth and Environmental Science 2
Which layer of Earth's atmosphere contains the ozone layer that protects life from harmful ultraviolet radiation?