BMST Earth's Geological Cycles 3 — Questions and Answers
Question 1: Which geological process causes rocks to break down into smaller particles at Earth's surface?
- Metamorphism
- Lithification
- Weathering (Correct answer)
- Subduction
Correct answer: Weathering
Weathering is the physical and chemical breakdown of rocks at or near Earth's surface into smaller fragments and minerals.
Question 2: In the nitrogen cycle, which process converts atmospheric nitrogen gas into a form usable by plants?
- Denitrification
- Nitrification
- Nitrogen fixation (Correct answer)
- Ammonification
Correct answer: Nitrogen fixation
Nitrogen fixation converts N₂ gas into ammonia or nitrates, primarily through bacteria in soil and plant root nodules.
Question 3: What term describes the process by which sediments are compacted and cemented together to form sedimentary rock?
- Crystallization
- Lithification (Correct answer)
- Foliation
- Deposition
Correct answer: Lithification
Lithification is the process by which loose sediments are compacted by pressure and cemented by minerals to form solid sedimentary rock.
Question 4: Which part of the rock cycle occurs when rocks are exposed to high heat and pressure without melting?
- Sedimentation
- Metamorphism (Correct answer)
- Crystallization
- Erosion
Correct answer: Metamorphism
Metamorphism transforms existing rocks through heat and pressure into metamorphic rocks without the rock melting completely.
Question 5: What is the term for water that flows over Earth's surface and eventually enters rivers and streams?
- Infiltration
- Percolation
- Groundwater
- Runoff (Correct answer)
Correct answer: Runoff
Runoff is precipitation that flows over land into rivers, lakes, and eventually the ocean rather than soaking into the ground.
Question 6: Which type of volcano typically forms at hot spots unrelated to tectonic plate boundaries?
- Stratovolcano
- Shield volcano (Correct answer)
- Cinder cone
- Composite volcano
Correct answer: Shield volcano
Shield volcanoes, like those in Hawaii, form over hot spots and are characterized by low-viscosity lava flows that build broad, gently sloping structures.
Question 7: In the carbon cycle, which natural process releases CO₂ back into the atmosphere?
- Photosynthesis
- Nitrogen fixation
- Cellular respiration (Correct answer)
- Transpiration
Correct answer: Cellular respiration
Cellular respiration in living organisms breaks down organic compounds and releases carbon dioxide back into the atmosphere.
BMST Earth's Geological Cycles 3
Which geological process causes rocks to break down into smaller particles at Earth's surface?