Deck 4: Archaeal Cell Structure

Question 1

A peptidoglycan-like polymer found in the cell walls of some Archaea is called __________.

Answer 1

pseudomurein

Question 2

Bacterial and archaeal ribosomes are known as _____ ribosomes,based on their sedimentation coefficient.

A)50S
B)30S
C)80S
D)70S

Answer 2

D

Question 3

_______ are the site of protein synthesis in the cell.

Answer 3

Ribosomes

Question 4

Some archaeons are symbionts in animal digestive tracts.

Question 5

Some archaeal cells lack a cell wall.

Question 6

The RNA polymerase enzymes of the Archaea are more similar to eukaryotic enzymes than to bacterial enzymes.

Question 7

The DNA of some archaeons is stabilized by association with archaeal histone proteins forming particles resembling eucaryotic nucleosomes.

Question 8

Cell walls of most Archaea and bacteria contain peptidoglycan.

Question 9

Archaeal flagella are superficially similar to bacterial flagella,although archaeal flagella are much thicker than bacterial flagella.

Question 10

Molecules or regions of molecules that readily interact with water are said to be __________,whereas molecules or regions of molecules that are insoluble in water or do not readily interact with water are said to be hydrophobic.

Question 11

Many archaeal genomes include chromosomes and plasmids.

Question 12

A(n)__________ layer is a layer of protein or glycoprotein that exhibits a pattern resembling floor tiles.

Question 13

External structures that are found in Archaea but not Bacteria are ___.

A)pili
B)flagella
C)hami
D)peptidoglycan

Question 14

A feature unique to some archaeal plasma membranes is that they may

A)consist of a lipid bilayer that lacks integral membrane proteins.
B)consist of a lipid bilayer with embedded proteins.
C)contain sterols such as cholesterol.
D)consist of a lipid monolayer.

Question 15

Archaeons have been isolated from temperate and cold environments.

Question 16

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

Question 17

_______ is a peptidoglycan-like molecule found in the cell walls of some archaea.

Question 18

Some methanogenic Archaea are capable of fixing nitrogen.

Question 19

The hydrocarbons found in the membranes of archaea are identical to those found in bacteria.

Question 20

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

Question 21

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

A)binary fission
B)budding
C)mitosis
D)fragmentation

Question 22

Unlike other prokaryotes,archaeons (except Sulfolobus)have two origins of replication.

Question 23

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

Question 24

Methanogens may contribute to the greenhouse effect and global warming due to methane production.

Question 25

Archaeal promoters are most similar to those of

A)viruses.
B)bacteria.
C)eukaryotes.
D)both viruses and bacteria.

Question 26

Because archaeons lack peptidoglycan in their cell walls

A)some have an outer layer of complex polysaccharide.
B)some have an outer layer of protein.
C)they must always be grown in isotonic medium.
D)some have an outer layer of complex polysaccharide and some have an outer layer of protein

Question 27

Methanogens can live only in __________ environments.

A)aerobic
B)anaerobic
C)microaerophilic
D)all of these

Question 28

The cell membranes of wall-less archaeons are strengthened by

A)diglycerol ethers.
B)glycoprotein or protein layers.
C)pseudomurein.
D)diglycerol tetraethers.

Question 29

Archaeal cell walls

A)are disrupted by treatment with lysozyme or penicillin.
B)are similar to those of gram-negative bacteria.
C)lack murein and D-amino acids.
D)include orthomureine.

Question 30

The Crenarchaeota and Euryarchaeota are

A)the two phyla of the Archaea.
B)very closely related based on 16S rRNA comparisons.
C)photosynthetic Archaea.
D)now classified with the bacteria based on genomic sequence analysis.

Question 31

Which of the following is not true about archaeal ribosomes?

A)They are 70S like bacterial ribosomes.
B)They may possess ribosome binding sites homologous to bacterial Shine-Dalgarno sequences.
C)They have similar antibiotic sensitivities to those of bacteria.
D)All of these are true about archaeal ribosomes.

Question 32

Archaeal membranes contain which of the following lipids?

A)phospholipids
B)sulfolipids
C)glycolipids
D)all of these

Question 33

Archaeal and Bacterial pili are identical in structure and function.

Question 34

Which of the following contribute(s)to the differences between the Archaea and the bacteria?

A)Archaea lack muramic acid.
B)Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids.
C)Archaea differ from bacteria in their tRNA composition,ribosome structure,and antibiotic sensitivity.
D)all of these.

Question 35

Archaeons are not known to incorporate (fix)carbon dioxide.

Question 36

Which of the following structures are external to both Bacterial and Archaeal cells?

A)ribosomes
B)hami
C)pili
D)peptidoglycan

Question 37

The Archaea generally lack which of the following that are normally found in gram-negative bacteria?

A)Outer membrane.
B)A complex peptidoglycan network.
C)Lipopolysaccharide.
D)All of the choices.

Question 38

Diglycerol tetraether lipids

A)are a characteristic feature of thermophilic Archaea.
B)tend to make the membrane less rigid.
C)are found in some bacteria and some Archaea.
D)form typical bilayer membranes in thermophilic Archaea of the genus Thermoplasma.

Question 39

Most archaeal mRNAs like those of eukaryotes are spliced.

Question 40

The primary lipid components of the membranes of extreme thermophiles are

A)sulfolipids.
B)cholesterol.
C)40 carbon diglycerol tetraethers.
D)20 carbon diglycerol diethers.