Many organisms that undergo chemosynthesis use ________ instead of ________ to fuel the processes that convert carbon dioxide into sugars.
a. energy; sunlight
b. hydrogen sulfide (H2S); sunlight
c. sunlight; water
d. sunlight; carbohydrates
e. sunlight; sulfuric acid
Answer:
b. hydrogen sulfide (H2S); sunlight
Explanation:
Some autotrophic organisms do not use the energy of sunlight to fix the inorganic simpler substances such as CO2 into the organic sugars. These organisms perform oxidation of chemical compounds. The energy released from the oxidation of organic or inorganic chemicals is used to fix CO2 into sugars. These organisms are called chemotrophs. Some chemotrophs such as sulfur-oxidizing bacteria use H2S as a source of energy to fix CO2.
