Okuma AnlamaSoru #11120
Life in the Deep Biosphere
For decades, biologists assumed that life was largely restricted to Earth's surface and the sunlit layers of the ocean. However, deep scientific drilling programs into continental rocks and oceanic crust have revealed a subterranean realm known as the "deep biosphere." Thousands of meters beneath the surface, under crushing lithostatic pressures and scorching temperatures exceeding one hundred degrees Celsius, billions of microorganisms flourish. Deprived of solar photons and atmospheric oxygen, these lithoautotrophic bacteria and archaea subsist on chemical energy released by serpentinization—a reaction between groundwater and minerals—and the radioactive decay of deep crustal isotopes. Remarkably, many of these subsurface microbes possess sluggish metabolic rates, dividing only once every several thousand years, effectively operating in near-geological timescales. According to the passage, microbes living in the deep subsurface crust ----.
- A)reproduce at lightning-fast speeds of once every few seconds
- B)depend entirely on sunlight filtering through miles of dense solid bedrock
- C)survive under extreme pressure and heat by drawing chemical energy from rock-water reactions
- D)were introduced by deep-sea drilling equipment contaminated in labs
- E)are identical to surface organisms that died millions of years ago
Cevabı ve çözümü göster
Doğru cevap: C) survive under extreme pressure and heat by drawing chemical energy from rock-water reactions
Çözüm: Metinde derin kabukta yaşayan mikropların (radiolysis ve kayaç-su tepkimeleriyle) kimyasal enerjiden yararlanarak aşırı basınç ve sıcaklıkta hayatta kaldığı anlatılır. Doğru cevap C'dir.