Micro Ch4

External structures that are found in Archaea but not Bacteria are _________. A. pili B. flagella C. hami D. peptidoglycan

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

Cell walls of most Archaea and bacteria contain peptidoglycan. True/False

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

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

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

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.

Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient. A. 50S B. 30S C. 80S D. 70S

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

The DNA of some archaeons is stabilized by association with archaeal histone proteins forming particles resembling eukaryotic nucleosomes. True/False

Many archaeal genomes include chromosomes and plasmids. True/False

Some archaeons are symbionts in animal digestive tracts. True/False

Some archaeal cells lack a cell wall. True/False

Unlike members of the Bacteria, most archaeans have linear chromosomes. True/False

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

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.

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.

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.

Archaeal membranes contain which of the following lipids? A. Phospholipids B. Sulfolipids C. Glycolipids D. All of the choices are correct.

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.

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.

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.

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.

The cell membranes of wall-less archaeons are strengthened by A. diglycerol ethers. B. glycoprotein or protein layers. C. pseudomurein. D. diglycerol tetraethers.

Which of the following structures are external to both Bacterial and Archaeal cells? A. Ribosomes B. Hami C. Pili D. Peptidoglycan

Archaeal and Bacterial pili are identical in structure and function. True/False

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.

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.

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

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

In terms of membrane lipids, the plasma membranes of archaeons are more similar to those of the eukaryotes than to membranes of bacteria. True/False

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.

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

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 peptdoglycan 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.

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.

Some researchers have suggested that archaeal flagella be renamed as archaella because A. they are more slender than bacterial flagella. B. some archaeon flagella don't have hooks. C. All of the choices are correct. D. archaean flagella are composed of more than one type of flagellin subunit. E. archaean flagella are solid and not hollow.

__________________ 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

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

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