BIOL 2051 Exam 1 (CH 1-6)

what structures do prokaryotes lack that are present in eukaryotes?

- membrane bound nucleus - membrane bound organelles - cytoskeleton - endoplasmic reticulum/Golgi apparatus (membranous cytoplasmic structures)

Who provided the evidence needed to discredit the concept of spontaneous generation?

Louis Pasteur

A strain of Neisseria gonorrhoeae has undergone a mutation and is no longer able to make pili. Predict the most likely outcome? a) The bacteria will become less virulent and will not be able to readily establish infection. b) The bacterial strain will no longer be able to transport certain sugars into the cell. c) The bacteria will become more virulent and will more readily establish infection. d) The bacteria will become more resistant to antibiotics.

a (The bacteria will become less virulent and will not be able to readily establish infection)

You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____. a) group translocation b) passive diffusion c) facillitated diffusion d) micronutrient regulator

a (group translocation)

The study of microbiology includes all of the following except_____. a) plants b) viruses c)bacteria d) fungi e) algae f) all of the above

a (plants)

The Archaea generally lack which of the following that are normally found in gram-negative bacteria? a) Lipopolysaccharide b) All of the choices are correct. c) A complex peptidoglycan network d) Outer membrane

b (all choices)

A newly discovered microorganism has a circular chromosome that is complexed with histones, but not enclosed within a membrane. The plasma membrane lipids include glycerol dietethers and diglycerol tetraethers. There are no mitochondria or chloroplasts, but the cells do contain 70s ribosomes. This microbe most likely is a) a fungus. b) a bacterium. c) an archaeon. d) a protozoan.

c (an archaeon)

Which group of microbes contains organisms necessary for production of wine and bread? a) Archaea b) Bacteria c) Fungi d) Algae

c (fungi)

__________________ 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.

cannulae; hami

Endospores are resistant to most environmental stressors because they have _____ complexed with calcium ions which stabilize DNA.

dipicolinic acid

external bacterial structure that is responsible for locomotion

flagellum

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.

hydrophilic

What disease did the first vaccination fight?

smallpox

A complete virus particle is called a

virion

Name one artificial method that is used to attack the bacterial cell wall.

B-lactam antibiotics (penicillin)

In what structure does respiration occur?

Cytoplasmic membrane (mitochondria!!)

The phospholipid of the plasma membrane in Bacteria is held together by what linkage?

Ester

T/F: Gram-positive bacteria have flagella with four basal body rings, while those of Gram-negative bacteria have only two.

False (Gram-positive bacteria have 2 basal body rings- Gram-negative have 4)

Which microscope typically uses dyes or antibodies?

Fluorescence

Antiseptic surgery was pioneered by

Joseph Lister

Name two structures that can be used for attachment in bacteria

Pili fimbriae (or capsule)

To avoid osmotic shock, extreme halophiles maintain a high intracellular concentration of what chemical?

Potassium (K+)

extreme halophiles maintain a high extracellular concentration of what chemical?

Sodium (Na+)

__________ is the process through which endospores are formed within a vegetative cell.

Sporulation

What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms? a) DNA molecules are more chemically stable than RNA molecules. b) DNA has deoxyribose rather than ribose. c) DNA is double-stranded rather than single-stranded.

a (DNA molecules are more chemically stable than RNA molecules)

Twitching motility involves a) type IV pili. b) periplasmic flagella. c) peritrichous flagella. d) monotrichous flagella.

a (type IV pili)

The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called

active transport

You did a gram stain but put too much ethanol. What will your smear look like under the microscope?

all cells would appear pink, assuming safranin was applied after

Check all of the following that showcases how microbes can be used by people. Check All That Apply: a) Production of breads b) Production of cheeses c) Production of antibiotics d) Production of vitamins e) Production of enzymes used for many different industrial applications

all of the above

Which of the following eukaryotes typically have cell walls? (Check all that apply.) a) Algae b) Protozoa c) Fungi d) Animals

all of the above

Lipids with polar and nonpolar ends are said to be

amphipathic

Cannulae are found in which domain of life?

archaea

Which of the following experiments is used to identify new pathogens? a) Stanley Miller experiment b) Koch postulates c) Pasteur's swan-neck experiment d) Endosymbiotic theory

b (Koch's postulates)

Which of the following bacterial groups is/are described CORRECTLY? a) Spirochetes - move by flagella movement b) Spirochetes - move by axial fibrils c) Spirochetes - move by axial fibrils and Nocardiae-form specialized dispersal cells on aerial mycelia d) Actinomycetes - reproduce by fragmentation e) Nocardiae - form specialized dispersal cells on aerial mycelia

b (Spirochetes - move by axial fibrils)

The bacterial flagellum moves ______. Multiple Choice a) in either a wave-like fashion or rotation that is powered by the proton motive force b) by rotation that is powered by the proton motive force c) in a wave-like fashion that is powered by the proton motive force d) by rotation that is powered by ATP e) in a wave-like fashion that is powered by ATP

b (by rotation that is powered by the proton motive force)

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 monolayer. c) contain sterols such as cholesterol. d) consist of a lipid bilayer with embedded proteins.

b (consist of a lipid monolayer)

You are trying to study the movement of a certain protozoan (protist, eukarya) species. What type of microscopy would be best? a) Bright-field b) Dark-field c)Electron microscopy d) two of the above e) all of the above

b (dark-field; Electron isn't necessary because the organism isn't extremely small; Bright-field would kill the organism and you wouldn't be able to study its movement)

Which of the following encodes its own capsid proteins? a) Prion b) Satellite virus c) Satellite RNA d) Satellite DNA

b (satellite virus)

Proteins function in modern cells as

both catalysts and structural elements

After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you shout: "Oops, I forgot the iodine step!" What would you expect to see if you observed the slide under the microscope?

both pink Gram-positve and Gram-negative cells

Which virion release process is most often used by enveloped viruses?

budding

Choose the incorrect statement about Koch's postulates. a) Isolating the microorganism from all cases of the disease b)Isolation of the microorganism in pure culture in the lab c) Infecting an animal model without causing symptoms of the same disease d) Infecting a suitable animal model and causing symptoms of the same disease

c (Infecting an animal model without causing symptoms of the same disease)

Penicillin inhibits bacterial growth by preventing the cross-linking during peptidoglycan synthesis. Why does penicillin not inhibit growth of archaeal cells? a) Pencillin is unable to penetrate the S layer to reach the peptidoglycan layer underneath. b) Archaeal cells do not have a cell wall. c) Most archaeal cells have a cell wall, but it is not composed of peptidoglycan. d) Penicillin is unable to penetrate the lipid outer membrane that blocks access of penicillin to the peptidogycan crosslinking enzymes.

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

The simplest viruses consist of a) Protein only. b) RNA, DNA and enzymes in a protein coat with a lipid envelope. c) RNA or DNA in a protein coat. d) RNA only. e) RNA or DNA in a protein coat covered with lipid envelope.

c (RNA or DNA in a protein coat)

Which of the following bacterial genera is/are described CORRECTLY? a) Corynebacterium - spore-forming rod and Clostridium - club-shaped rod b) Corynebacterium - spore-forming rod c)Vibrio - curved rod d) Clostridium - club-shaped rod e) Corynebacterium - spore-forming rod and Vibrio-curved rod

c (Vibrio - curved rod)

The Gram stain of a bacterial cell is based on the chemical properties of its ________.

cell wall

Ability to be distinguished from the surroundings

contrast

The spore layer containing peptidoglycan is the ______.

cortex

The proper sequence of reagents in the Gram stain procedure is

crystal violet, iodine, ethanol, safranin

Select a harmful effect that can result from bacterial colonization of the human body. a) Immune system development b) Production of vitamins c) Digestion of food d) Invasion of host cells

d (Invasion of host cells)

Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease? a) Fracastoro b)Pasteur c)Lister d)Koch

d (Robert Koch)

Which of the following structures is NOT found in an endospore? a) Exosporium b) Coat c) Core d) Capsule

d (capsule)

The plasma membrane of eukaryotes contains all of the following EXCEPT a) sterols. b) phosphoglycerides. c) sphingolipids. d) peptidoglycan.

d (peptidoglycan)

Which of the following structures are external to both Bacterial and Archaeal cells? Multiple Choice a) Hami b) Ribosomes c) Peptidoglycan d) Pili

d (pili)

Which statement about flagellar structure is TRUE? a) The basal body is a short curved segment. b) The hook anchors the flagellum in the cell membrane and the filament extends out of the cell. c) The hook anchors the flagellum in the cell membrane. d) The filament extends out of the cell. e) The hook anchors the flagellum in the cell membrane,the basal body is a short curved segment, and the filament extends out of the cell.

d (the filament extends out of the cell)

Prions are of significance because they cause infections of

domestic animals and humans

Which of the following would be a reasonable estimate of the number of bacteria on earth? a) 5X10^1 b) 5X10^5 c) 5X10^10 d)5X10^18 e) 5X10^30

e (5X10^30)

Which of the following cocci cell arrangements is/are described CORRECTLY? a) Streptococci - Grape-like clusters of spherical cells b) Staphylococci - Chains of spherical cells c) Staphylococci - Chains of spherical cells and streptococci - Grape-like clusters of spherical cells d) Staphylococci - Chains of spherical cells, streptococci - Grape-like clusters of spherical cells, and diplococci - Pairs of spherical cells e) Diplococci - Pairs of spherical cells

e (Diplococci - Pairs of spherical cells)

Gliding motility in bacteria involves which of the following? a) Flagella b) Specialized cell-surface proteins, flagella, and slimy polysaccharides c) Slimy polysaccharides d) Specialized cell-surface proteins e) Specialized cell-surface proteins and slimy polysaccharides

e (Specialized cell-surface proteins and slimy polysaccharides)

The nucleic acids carried by viruses usually consist of

either DNA or RNA

The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as

endotoxin

the______is a membranous layer that can be found in some viruses.

envelope

The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.

eukarya

Sterols are virtually always present in_________ but absent in_________

eukaryotic membranes; prokaryotic membranes

T/F: A temperate phage always lyses its host cell.

false

T/F: A viroid is a virus that lacks a capsid.

false

T/F: Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.

false

T/F: Cell walls of most Archaea and bacteria contain peptidoglycan.

false

T/F: Gram-positive bacteria have a structurally and chemically more complex cell wall than gram-negative bacteria.

false

T/F: Like prokaryotic cells, most eukaryotic cells have an external cell wall.

false

T/F: Microbiologists study a variety of organisms, but all are considered either Bacteria or Archaea.

false

T/F: Robert Koch developed a vaccine that could be used to prevent anthrax.

false

T/F: The Gram stain can only be performed on cultures grown in liquid media.

false

T/F: The leading cause of death in the US today are caused mainly by infectious diseases.

false

T/F: Viruses and bacteria were first cultured in the laboratory at about the same time.

false

T/F: Viruses are not generally studied by microbiologists because they are not classified as living organisms.

false

T/F: Viruses constitute the fourth domain of life in current biological classification schemes.

false

T/F: Viruses have typical cellular structure like other living organisms.

false

T/F: Gram-positive bacteria have a thinner layer of peptidoglycan than gram-negative bacteria.

false (Gram-positive have a thicker layer of peptidoglycan)

T/F: In an endospore, the protein coat forms a layer external to the exosporium.

false (exosporium is a layer formed external to the protein coat)

T/F: Edward Jenner's work in preventing rabies led to the use of the term vaccination to describe a type of procedure used in the prevention of disease.

false (he created first vaccine for smallpox from cowpox)

T/F: Most bacterial cells are around 10 to 100mm in size

false (largest bacteria is 0.7mm in size- smallest is 0.3um)

T/F: Endospores can only be formed by some Gram-negative bacteria.

false (only present in some Gram-positive bacteria)

T/F: Endospores are reproductive structures.

false (survival structures)

external bacterial structure that is responsible for bacterial attachment to surfaces

fimbriae

__________ is the main part of the process through which a vegetative cell is formed from an endospore.

germination

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

hami

Enzymes needed to digest all types of macromolecules are found in

lysosomes

The apparent increase in size of an image

magnification

n endospore formation, when DNA condenses and aligns itself in the center of the cell, the cell is called a(n) ______.

mother cell

Can nucleic acids be broken down?

no. you will die

What is the most important macromolecule?

nucleic acid

In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the

nucleocapsid

In prokaryotes, DNA is found mainly in the ________.

nucleoid

Name one double-membrane bound organelle that is found in eukaryotic cells.

nucleus (or mitochondria, chloroplast)

Genes whose expression (or abnormal expression) causes cancer are called

oncogenes

Membrane delimited intracellular structures that perform specific functions in cells are called

organelles

In addition, there is a (n) ______external to the Gram-negative bacterial peptidoglycan layer.

outer membrane

The Golgi apparatus is responsible for the

packaging of materials for excretion

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called

passive diffusion

The plasma membrane in Gram-negative bacteria contains only a thin layer of _______

peptidoglycan

The two layer cell wall of Gram-negative bacteria is separated from the plasma membrane by the _________

periplasmic space

Viroids are of economic significance because they cause disease in

plants

Most enveloped viruses use the host __________ membrane as their envelope source.

plasma

The cell wall of Gram-negative bacterial cells is external to the _______

plasma membrane

In general, what two structures are found in the cell envelope of bacteria?

plasma membrane cell wall

Bacterial cells that are variable in shape are called

pleomorphic

Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called

prokaryotes

RNA serves to convert the information stored in DNA to ________.

protein

The power used by most bacterial flagellar motors is produced by

proton motive foce (PMF)

The ability to distinguish between two separate structures that are very close to one another

resolution

_______ are the site of protein synthesis in the cell.

ribosomes

Endoplasmic reticulum (ER) with many ribosomes attached is called __________ ER, whereas endoplasmic reticulum that is mostly devoid of ribosomes is called __________ ER.

rough; smooth

The bacterium E. coli swims in a straight line, called a __________, for a few seconds; then it stops, tumbles, then swims away in a new direction.

run

What microscope would be the best to use to view cell surface features of a specimen?

scanning electron microscope

external bacterial structure that is responsible for transferring DNA from one bacterial cell to another

sex pilus

the concept that living organisms arise from nonliving material is called

spontaneous generation

The formation of carbohydrate (CO2 fixation) in the dark reaction of photosynthesis, takes place in the

stroma

what is the biological function of endospores?

they enable organisms to endure extremes of temperature, drying, and nutrient depletion

What would be the best technique to prepare and view the internal structures of fungal hyphae?

transmission electron microscopy

T/F: Acetone can be used as the decolorizer in the Gram stain procedure.

true

T/F: All eukaryotes have a membrane-delimited nucleus.

true

T/F: Chloroplasts are the site for both the light and dark reactions of photosynthesis.

true

T/F: Mycoplasma pneumoniae lacks a cell wall and are pleomorphic in shape.

true

T/F: Some archaeal cells lack a cell wall.

true

T/F: Spirillum is a genus of spiral-shaped bacteria that move by flagella.

true

T/F: Spirochetes move in a screw-like manner that is mediated by bundles of flagella located in the cell's periplasmic space.

true

T/F: Spore formation is initiated when there is a scarcity of nutrients.

true

T/F: Sterol-like molecules called hopanoids are thought to be important for the structural integrity of many bacteria because of their suspected role in membrane stabilization.

true

T/F: The endosymbiotic hypothesis is generally accepted as the origin of two eukaryotic organelles: mitochondria and chloroplasts.

true

T/F: The membrane bound structure that contains the chromosomes of eukaryotes is called the nucleus.

true

T/F: in bacteria, poly-B-hydroxybutyrate and sulfur globules are inclusion bodies that can serve as an energy source.

true (as well as glycogen, polyphosphate, nd carboxysomes)

The term used to describe bacteria that are shaped like curved rods is

vibrios

Which type of phage always lyses its host cell?

virulent

Can you break down proteins for energy?

yes, carbs and lipids