Question

In 2005, a team of scientists discovered a photosynthetic bacteria living near the molten lava of a thermal vent ecosystem deep in the Pacific Ocean. The bacteria lived 2400 meters below the surface of the ocean, yet made energy from photosynthesis. Which conclusion best explains the results?
a. Photosynthesis can occur without light.
b. The hydrothermal vent emits usable light.
c. High water pressure can power photosynthesis.
d. The bacteria used to live at the ocean’s surface.

Answer 1

Answer: B

Explanation: Since sunlight does not reach deep-sea hydrothermal vents, organisms in deep-sea hydrothermal vents cannot obtain energy from the sun to perform photosynthesis. Instead, the microbial life found at hydrothermal vents are chemosynthetic; they fix carbon by using energy from chemicals such as sulfide, as opposed to light energy from the sun.