Questions on Mass Extinction (Ecology)
Multiple-Choice Questions: Mass Extinction (Ecology)
1. What is the definition of a mass extinction?
A) The extinction of a single species over time
B) A decline in population of predators
C) A widespread and rapid decrease in biodiversity affecting many species
D) The extinction of plants only
E) A natural increase in species diversity
2. How many major mass extinction events are generally recognized in Earth's history?
A) Three
B) Four
C) Five
D) Six
E) Seven
3. The most severe mass extinction event occurred at the end of which geological period?
A) Jurassic
B) Permian
C) Cretaceous
D) Devonian
E) Triassic
4. What percentage of marine species is estimated to have gone extinct during the Permian-Triassic extinction?
A) 25%
B) 50%
C) 70%
D) 90%
E) 100%
5. Which mass extinction event led to the extinction of non-avian dinosaurs?
A) Ordovician-Silurian
B) Devonian
C) Permian-Triassic
D) Cretaceous-Paleogene
E) Triassic-Jurassic
6. The Cretaceous-Paleogene extinction is widely believed to have been caused by:
A) Human activity
B) Ice age
C) A large asteroid impact
D) Continental drift
E) Overhunting
7. What is the name of the crater associated with the Cretaceous mass extinction?
A) Mariana Trench
B) Yellowstone Caldera
C) Chicxulub Crater
D) Mid-Atlantic Ridge
E) Crater Lake
8. Which gas, often released by volcanic activity, contributes to mass extinction by altering the climate?
A) Oxygen
B) Helium
C) Carbon dioxide
D) Nitrogen
E) Argon
9. Which extinction event is linked to massive volcanic eruptions called the Siberian Traps?
A) Devonian
B) Permian-Triassic
C) Triassic-Jurassic
D) Cretaceous-Paleogene
E) Ordovician
10. Which of the following is not typically a cause of mass extinctions?
A) Asteroid impacts
B) Volcanism
C) Climate change
D) Mutation
E) Sea level changes
11. Which group of animals dominated Earth after the extinction of the non-avian dinosaurs?
A) Reptiles
B) Fish
C) Amphibians
D) Mammals
E) Insects
12. Which extinction event occurred around 444 million years ago and affected marine life most severely?
A) Triassic-Jurassic
B) Ordovician-Silurian
C) Cretaceous-Paleogene
D) Devonian
E) Cambrian Explosion
13. What distinguishes a mass extinction from background extinction?
A) It occurs gradually
B) It affects only plants
C) It is more rapid and widespread
D) It increases biodiversity
E) It is caused only by humans
14. What term refers to the current biodiversity crisis believed to be the sixth mass extinction?
A) Modern bottleneck
B) Human fallout
C) Anthropocene extinction
D) Post-dinosaur event
E) Biodiversity boom
15. Which human activities contribute significantly to the current mass extinction?
A) Space exploration
B) Deforestation, pollution, and habitat loss
C) Genetic engineering
D) Time travel
E) Cloud computing
16. Which group of organisms is currently experiencing the highest extinction rates?
A) Amphibians
B) Birds
C) Mammals
D) Reptiles
E) Algae
17. What is one major consequence of mass extinction events?
A) Immediate recovery of ecosystems
B) Expansion of surviving species into new niches
C) Total sterilization of Earth
D) Reduction of geological activity
E) Instant climate stabilization
18. How long can ecosystems take to recover after a mass extinction event?
A) 10 years
B) 100 years
C) 1,000 years
D) 1 million years or more
E) They never recover
19. What is a biotic cause of extinction?
A) Asteroid impact
B) Volcanic eruption
C) Predation or disease
D) Ocean acidification
E) Solar flare
20. Which strategy helps prevent or reduce the impact of modern extinction?
A) Increasing greenhouse gas emissions
B) Promoting monoculture farming
C) Habitat conservation and restoration
D) Introducing invasive species
E) Deforestation for agriculture
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Answer Key with Explanations
1. C – A mass extinction is a rapid and widespread loss of a large number of species.
2. C – There have been five recognized mass extinctions in Earth's history.
3. B – The Permian-Triassic extinction is the most severe known extinction event.
4. D – Around 90% of marine species were wiped out during the Permian-Triassic extinction.
5. D – The Cretaceous-Paleogene extinction caused the end of non-avian dinosaurs.
6. C – A massive asteroid impact is the leading theory for this event.
7. C – The Chicxulub Crater in Mexico is linked to the asteroid that struck 66 million years ago.
8. C – Carbon dioxide from volcanoes can cause global warming and ocean acidification.
9. B – The Siberian Traps are linked to the Permian-Triassic mass extinction.
10. D – Mutation is a natural process and not a primary cause of mass extinction events.
11. D – Mammals expanded into new ecological roles after dinosaurs went extinct.
12. B – The Ordovician-Silurian extinction was a major marine extinction.
13. C – Mass extinctions are rapid, global, and involve a large proportion of species.
14. C – The Anthropocene extinction refers to human-driven biodiversity loss.
15. B – These human actions are driving species to extinction today.
16. A – Amphibians are extremely sensitive to environmental changes and are declining rapidly.
17. B – Surviving species often diversify and occupy new niches.
18. D – Recovery from mass extinctions can take millions of years.
19. C – Biotic causes include biological factors like predation, competition, and disease.
20. C – Protecting habitats is key to maintaining biodiversity and preventing extinction.
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