Exam 18: The Archaea

Defining features of the halobacteria include

The photosynthetic membrane of Halobacterium salinarium contains

Although Sulfolobus solfataricus grows at pH 2 to 4, it maintains a cytoplasmic pH of about 2, thereby generating a large pH gradient across the plasma membrane.

Unlike members of the Bacteria, most archaeons have linear chromosomes with multiple origins of replication.

Glycogen is used as a major carbon and energy reserve by some archaeons.

An organism with a temperature growth optimum near 80 $\degree$ C and a pH growth optimum between 2 and 3 is usually referred to as a(n)

Which of the following do methanogens not use to form methane?

The Archaea do not use __________ as a mechanism for reproduction.

Many species in the phylum Crenarchaeota are considered extreme thermophiles or ________________, which can grow at temperatures above 100 degrees C.

Which of the following is true about the cell-wall-less archaeal genus Thermoplasma?

The primary lipid components of the membranes of extreme thermophiles are

If the NaCl concentration drops below 1.5 M the cell walls of Halobacterium disintegrate.

Which of the following is currently the largest group of cultured Archaea?

Which of the following is/are true of most of the extreme thermophilic Archaea in the phylum of Crenarchaeota?

A modified cell membrane that carries out photosynthesis using bacteriorhodopsin in the absence of chlorophyll is called a __________ membrane.

Methanogens can live only in __________ environments.

Archaeons have been isolated from temperate and cold environments.

A large number of the genes shared only by bacteria and Archaea produce proteins that are involved in ____________ ___________.

Because archaeons lack peptidoglycan in their cell walls

Which of the following genera of the Archaea do not have cell walls?