Ch4 Archaeal Cell Structure Exam Prep

Prescott's Microbiology, 11e (Willey)

Chapter 4 Archaeal Cell Structure

1) 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 ________.

2) External structures that are found in archaea but not bacteria are ________.

A) pili

B) flagella

C) hami

D) peptidoglycan

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

4) Cell walls of most archaea and bacteria contain peptidoglycan.

5) ________ is a peptidoglycan-like molecule found in the cell walls of some archaea.  

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

7) ________ are the site of protein synthesis in the cell.

8) Archaeal flagella (archaella) are superficially similar to bacterial flagella, although archaella are much thicker than bacterial flagella.

9) 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

10) Bacterial and archaeal ribosomes are known as ________ ribosomes, based on their sedimentation coefficient.

A) 50S

B) 30S

C) 80S

D) 70S

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

12) Many archaeal genomes include chromosomes and plasmids.

13) Some archaeons are symbionts in animal digestive tracts.

14) Some archaeal cells lack a cell wall.

15) Unlike members of domain Bacteria, most archaeans have linear chromosomes. 

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

17) Which statement correctly describes archaeal cell walls?

A) Some have an outer layer of complex polysaccharide.

B) Some have an outer layer of protein.

C) Many have peptidoglycan.

D) Some have an outer layer of complex polysaccharide and some have an outer layer of protein.

18) 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) Differences in rRNA nucleotide sequences led to the division of the prokaryotes into two separate taxa.

19) 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

20) Archaeal membranes contain which of the following lipids?

A) Phospholipids

B) Sulfolipids

C) Glycolipids

D) All of the choices are correct.

21) 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 are correct.

22) Which of the following contribute(s) to the differences between the members of the Domain Archaea and the Domain 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 the choices are correct.

23) 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) are unlike bacterial cells; they all have the same composition

24) 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

25) The cell membranes of archaeons that lack a cell wall are strengthened by ________.

A) diglycerol ethers

B) glycoprotein or protein layers

C) pseudomurein

D) diglycerol tetraethers

26) Which of the following structures are external to both bacterial and archaeal cells?

A) Ribosomes

B) Hami

C) Pili

D) Peptidoglycan

27) Archaeal and bacterial pili are identical in structure and function.

28) Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells?

A) Archaeal cells do not have a cell wall.

B) Most archaeal cells have a cell wall, but it is not composed of peptidoglycan.

C) Penicillin is unable to penetrate the lipid outer membrane that blocks access of penicillin to the peptidogycan crosslinking enzymes.

D) Pencillin is unable to penetrate the S layer to reach the peptidoglycan layer underneath.

29) One type of archaeon, Haloquadratum walsbyi, is shaped like a postage stamp with dimensions of 2 µm x 3 µm x 0.25 µm. What advantage would this shape provide?

A) This shape enables this bacteria to float on surfaces and obtain better light exposure.

B) This shape increases the surface to volume ratio enabling more efficient nutrient uptake.

C) This shape is difficult for phagocytic cells to attach to and engulf.

D) This shape is more conducive to the formation of biofilm communities.

30) Which cellular shape is seen among members of domain Bacteria that is not found among the domain Archaea?

A) Cocci

B) Bacilli

C) Comma-shaped

D) Spiral or corkscrew shapes

31) You are studying a newly discovered prokaryotic microorganism and are attempting to determine whether it will be classified in the domain Bacteria or in the domain Archaea. All of the following would be helpful in making that distinction except ________.

A) sequence of small subunit ribosomal RNA

B) type of membrane lipids

C) presence or absence of peptidoglycan in cell walls

D) presence or absence of double-stranded circular DNA genome

32) In terms of membrane lipids, the plasma membranes of archaeons are more similar to those of the eukaryotes than to membranes of bacteria.

33) Which of the following is the most unique aspect of archaeon cell envelopes?

A) The plasma membrane is composed of phospholipids.

B) The cell walls contain a modified type of peptidoglycan.

C) Archaeon capsules can be composed of protein or polysaccharide.

D) Some archaeons have lipid monolayers in their plasma membrane.

34) Which type of membrane transport is most important for nutrient acquisition in nutrient poor environments?

A) Simple diffusion

B) Facilitated diffusion through channel proteins

C) Facilitated diffusion through membrane carrier proteins

D) Active transport

35) Which statement correctly explains the Gram-stain reaction of archaeal cells?

A) They are Gram-positive due to the pseudomurein layer in their cell walls.

B) They are Gram-negative due to the lack of peptidoglycan in their cell walls.

C) They don't stain – basic dyes used in the Gram stain don't adhere to archaeal cells.

D) Some are Gram-positive and some are Gram-negative due to the diverse chemical structure.

36) Select the correct statement about archaeal ribosomes.

A) Archaeal ribosomal proteins are more similar to bacterial ribosomal proteins than to eukaryotic ribosomal proteins.

B) Archaeal ribosomes are susceptible to antibiotics, similar to bacterial ribosomes.

C) Archaeal ribosomes have subunits that are identical in shape and chemical components to those of bacteria.

D) The chemical components of archaean ribosomes are more similar to those of eukaryotic ribosomes than to those of bacterial ribosomes.

37) In order to distinguish them from bacterial flagella, archaeal flagella have been renamed as archaella because ________.

A) they are more slender than bacterial flagella

B) some archaeon flagella don't have hooks

C) archaean flagella are solid and not hollow

D) archaean flagella are composed of more than one type of flagellin subunit

E) All of the choices are correct.

38) ________ are hollow tube-like structures that hold some archaeal daughter cells together after cell division while___________ are grappling hook-like structures that appear to attach archaeal cells to surfaces.

A) Pili; hami

B) Cannulae; hami

C) Hami; fimbriae

D) Cannulae; pili

39) Archaeons power their flagella by proton motive force (PMF), whereas bacteria empower their flagella by ATP hydrolysis.

40) You are working with a newly described microorganism that has flagella that are solid, 10 nm in diameter, and composed of more than one type of flagellin subunit. Based on the type of flagella, which type of organism is this?

A) Archaea

B) Bacteria

C) Protozoa

D) Algae

41) Archaea often live in nutrient-poor environments. In order to ensure survival, they must ________.

A) accumulate nutrients inside the cell at higher concentrations than the external environment, which requires active transport mechanisms

B) acquire nutrients inside the cell at lower concentrations than the external environment, which requires passive transport mechanisms

C) transport nutrients to the outside of the cell by facilitated diffusion

D) develop metabolic pathways to synthesize their own nutrients using cytoplasmic molecules

42) A fundamental difference between bacterial and archaeal membranes is that ________.

A) bacterial membranes are always comprised of phospholipid bilayers, whereas archaeal membranes can be bilayers or monolayers

B) the phospholipids in archaea are comprised of a glycerol molecule and three fatty acids vs. two fatty acids in bacteria

C) archaeal membranes must be able to solidify due to the extreme habitats the organisms occupy

D) archaeal membranes have a hydrophobic exterior and a hydrophilic interior vs. the reverse in bacterial membranes