Final answer:
The true statement about archaea that produce methane is that they are methanogens. Methanogens have the ability to reduce carbon dioxide in the presence of hydrogen, producing methane, and can thrive in diverse extreme environments.
Step-by-step explanation:
Archaea that produce methane are called methanogens. Methanogens are a type of archaea that can reduce carbon dioxide in the presence of hydrogen, producing methane as a metabolic waste product. They are known for living in extreme environments, but can also be found in common environments like soil.
Archaea that produce methane are known as methanogens. These single-celled, prokaryotic organisms are not only remarkable for their ability to produce methane as a metabolic waste product but are also known for their resilience in extreme environments. One of the unique characteristics of methanogens is their capability to reduce carbon dioxide in the presence of hydrogen, which results in the production of methane.
Although some archaea are adaptive to environments such as high salinity (halophiles) or high temperature (thermophiles), it is methanogens that are the specific group responsible for methane production. Methanogens can be found in various extreme settings, ranging from hot springs to beneath ice sheets. They do not necessarily require extreme salt conditions like halophiles or high-temperature habitats like thermophiles.