Sub-Bagian 1: Teks Ekspositori Sains (Soal 1 – 10)
Passage 1: The Complexities of Deep-Sea Hydrothermal Vents
Hydrothermal vents are often hailed as isolated ecosystems, thriving without reliance on solar energy. However, the energy source is not entirely internal. Chemical energy derived from volcanic sulfur compounds, a process known as chemosynthesis, sustains the primary producers—chemoautotrophic bacteria. This unique environment, characterized by extreme temperature gradients and high pressure, challenges long-held biological assumptions about necessary conditions for life. The fluid expelled by the vents, rich in dissolved minerals, forms structures often referred to as 'black smokers,' depositing valuable metals onto the ocean floor. Despite the extreme conditions, the sheer biomass supported by these vents is remarkably dense, dominated by tube worms, clams, and specialized shrimp, many of which have symbiotic relationships with the chemosynthetic bacteria. The discovery of these vents transformed astrobiology, proving that life can flourish in conditions previously deemed impossible.