Question

The primary producers of the deep hypothermal vent ecosystem are
A. Blue green algae
B. Coral reefs
C. Green algae
D. Chemosynthetic bacteria

Answer 1

Hint: A hydrothermal vent from which geothermally heated water issues is a fissure on the seafloor. Hydrothermal vents are commonly found in areas where tectonic plates are moving apart at spreading centers, near volcanically active places, ocean basins, and hotspots.

Complete answer:
The primary producers are archaebacteria of the deep hydrothermal vent ecosystem.
The two different types of hydrothermal vents; Black Smokers, and White Smokers.
Chemosynthetic bacteria are the primary producers of the deep-sea hydrothermal vent ecosystem. Sulfide-oxidizing bacteria are chemolithotrophic in nature. The invertebrates found in the immediate vicinity of the vent ecosystem, the hypothermal vents provide the primary food.
Deep hydrothermal vents lack oxygen and are anaerobic sites. Blue-green algae, coral reefs, and green algae are aerobic photoautotrophs and cannot survive without sunlight and oxygen.
Chemotrophs are the organisms that use as the source of energy either organic or inorganic compounds. Hence can survive under deep hydrothermal vents that are devoid of sunlight.
Cyanobacteria also called Blue-green algae, are any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms.
A coral reef is characterized by reef-building corals, is an underwater ecosystem. Reefs are held together by calcium carbonate and formed of colonies of coral polyps.
Green algae-photosynthetic algae which store starch in discrete chloroplasts and contain chlorophyll.

Hence, the correct answer is option (D).

Note: Primary producers are those who produce their own food in the presence of sunlight and serves as food for the successive level in the food chain. Deep hydrothermal vents are anaerobic sites and hence lack oxygen. Green sulfur bacteria are found in deep hypothermal vents. Chemotrophs use the organic or inorganic source as electron donors, oxygen is not produced and the surroundings are anaerobic.