GED Science Earth and Space Science 3 — Questions and Answers
Question 1: Which layer of Earth's atmosphere contains the ozone layer that absorbs most of the Sun's ultraviolet radiation?
- Troposphere
- Stratosphere (Correct answer)
- Mesosphere
- Thermosphere
Correct answer: Stratosphere
The ozone layer sits within the stratosphere, roughly 15–35 km above Earth's surface, where it absorbs harmful UV-B and UV-C radiation.
Question 2: What process causes the formation of igneous rocks?
- Compaction and cementation of sediments
- Cooling and solidification of magma or lava (Correct answer)
- Heat and pressure transforming existing rock
- Chemical weathering of limestone
Correct answer: Cooling and solidification of magma or lava
Igneous rocks form when molten rock (magma underground or lava at the surface) cools and solidifies.
Question 3: A star appears to change position slightly against distant background stars when viewed six months apart. This effect is called:
- Parallax (Correct answer)
- Redshift
- Aberration
- Precession
Correct answer: Parallax
Stellar parallax is the apparent shift in a nearby star's position due to Earth's orbital motion around the Sun, and it is used to measure stellar distances.
Question 4: Which type of boundary is associated with the formation of deep ocean trenches?
- Divergent boundary
- Transform boundary
- Convergent boundary (Correct answer)
- Hot-spot boundary
Correct answer: Convergent boundary
At convergent boundaries, one tectonic plate subducts beneath another, forming deep ocean trenches such as the Mariana Trench.
Question 5: The water cycle process by which plants release water vapor through their leaves is called:
- Transpiration (Correct answer)
- Evaporation
- Condensation
- Precipitation
Correct answer: Transpiration
Transpiration is the release of water vapor from plant leaves through tiny pores called stomata, contributing significantly to the water cycle.
Question 6: What causes the seasons on Earth?
- Changes in Earth's distance from the Sun
- The tilt of Earth's axis relative to its orbital plane (Correct answer)
- Variations in the Sun's energy output
- The Moon's gravitational pull on Earth
Correct answer: The tilt of Earth's axis relative to its orbital plane
Earth's 23.5° axial tilt causes different hemispheres to receive more direct sunlight at different times of year, creating seasons.
Question 7: Which type of seismic wave cannot travel through liquid layers of Earth and is therefore blocked by the outer core?
- P-waves (primary waves)
- S-waves (secondary waves) (Correct answer)
- Surface waves
- Love waves
Correct answer: S-waves (secondary waves)
S-waves are shear waves that require a solid medium; they cannot travel through Earth's liquid outer core, creating a seismic shadow zone.
GED Science Earth and Space Science 3
Which layer of Earth's atmosphere contains the ozone layer that absorbs most of the Sun's ultraviolet radiation?