Okuma AnlamaSoru #9360
Deep-Sea Hydrothermal Vents and the Origins of Life
Until the late 1970s, marine biologists operated under the foundational assumption that all life on Earth fundamentally depended on photosynthetic energy derived from solar radiation. That paradigm shattered in 1977 when the deep-sea research submersible Alvin discovered hydrothermal vents along the Galápagos Rift, two and a half kilometers beneath the ocean surface. Here, superheated water reaching temperatures above 400°C spews from mineral chimneys known as "black smokers," rich in hydrogen sulfide and dissolved metals. In this perpetual abyss of utter darkness and crushing pressure, scientists discovered flourishing ecosystems teeming with giant tube worms, blind shrimp, and pale crabs. Instead of photosynthesis, the foundation of this thriving food web is chemosynthesis, driven by extremophile bacteria that oxidize toxic hydrogen sulfide to produce organic carbon. Many astrobiologists now hypothesize that life on Earth may have originated around such alkaline vents, and that analogous chemosynthetic ecosystems might exist today in the subsurface ice-covered oceans of Europa and Enceladus. Why are astrobiologists particularly interested in deep-sea hydrothermal vents?
- A)Because water spewing from vents does not contain any chemical minerals or dissolved ions
- B)Because the mineral chimneys contain vast reserves of commercial gold and rare earth elements
- C)Because hydrothermal vents have proven that human colonies can survive on the ocean floor indefinitely
- D)Because the Alvin submersible can be converted into an interplanetary space vehicle
- E)Because identical chemosynthetic ecosystems might exist in the ice-covered oceans of icy moons like Europa and Enceladus
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Doğru cevap: E) Because identical chemosynthetic ecosystems might exist in the ice-covered oceans of icy moons like Europa and Enceladus
Çözüm: Metnin son cümlesinde astrobiyologların Dünya'da yaşamın bu tür bacalarda başlamış olabileceğini ve benzer kemosentetik ekosistemlerin Europa ve Enceladus uydularının buz altı okyanuslarında var olabileceğini düşündükleri ifade edilmiştir. Doğru cevap E'dir.