therefore contributes to global warming (see theEnvironmental Problemschapter). There-
fore, the rate of methane released in swamps is of interest to scientists studying climate
change.
Figure 8.13: Cows are able to digest grass with the help of the methanogens in their gut. ( 9 )
Although archaea are known for living in unusual environments, like the Dead Sea, inside hot
springs, and in the guts of cows, they also live in more common environments. For example,
new research shows that archaea are abundant in the soil and among the plankton in the
ocean. Therefore, scientists are just beginning to discover some of the important roles that
archaea have in the environment.
Lesson Summary
- Archaea are prokaryotes that differ from bacteria somewhat in their DNA and bio-
chemistry. - Most archaea are chemotrophs but some are photosynthetic or form mutualistic rela-
tionships. - Archaea reproduce asexually through binary fission, fragmentation, or budding.
- Archaea are known for living in extreme environments.
Review Questions
- What domains include the prokaryotes?
- How are the cell walls of archaea different from those of bacteria?