Exam 4 Flashcards
Microbiology is the study of microbes. These include all but which of the following?
A. Archaea
B. Bacteria
C. Viruses
D. Plants
Plants
What general feature is necessary to consider an organism a microbe?
A. small enough that a microscope is required to see them
B. heterotrophic
C. sexual reproduction
D. use aerobic respiration for metabolism
small enough that a microscope is required to see them
Miller’s laboratory experiments showed that:
A. it is possible to form protocells.
B. the primitive gases can react together to produce small organic molecules.
C. atmospheric pressure is required for life to begin.
D. the earth is approximately 4.5 billion years old.
the primitive gasses can react together to produce small organic molecules
Which of the following kinds of molecules is thought to have been absent from the primitive reducing atmosphere?
A. water vapor (H2O)
B. methane (CH4)
C. hydrogen (H2)
D. oxygen (O2)
oxygen (O2)
Considering the various theories, the energy used in forming organic molecules in the primitive atmosphere could have come from all EXCEPT
A. lightning.
B. ultraviolet radiation.
C. heat from volcanoes.
D. sound.
sound
What is the evolutionary relationship among archaea, bacteria, and eukarya?
A. Since archaea are the most primitive, archaean ancestors gave rise to bacteria that in turn gave rise to eukaryotes.
B. All three domains are equally distant from the most primitive common ancestor, a protocell.
C. Archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea.
D. Bacterial ancestors gave rise to both archaea and to eukaryotes as two separate side branches.
archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea
A new classification by domains separates prokaryotes into
A. Bacteria and Cyanobacteria.
B. photosynthetic bacteria and chemosynthetic bacteria.
C. Archaea and Bacteria.
D. autotrophs and heterotrophs.
archaea and bacteria
Bacterial cells pick up free pieces of DNA from the medium pieces that were released from dead bacteria in a process called
A. transformation.
B. transduction.
C. conjugation.
D. replication.
transformation
Which of these is a correct description of a form of horizontal gene transfer in bacteria?
A. Crossing-over occurs between paired chromosomes in meiosis.
B. Conjugation occurs when a cell passes DNA to another cell by means of a sex pilus.
C. Transformation occurs when a bacteriophage carries a bit of DNA from a previous host cell to a new host cell.
D. Transduction occurs when a live bacterium picks up DNA from dead bacteria that have shed it into the environment of the living cell.
conjugation occurs when a cell passes DNA to another cell by means of a sex pilus
One bacterial cell passes DNA to a second cell through a sex pilus in the process of
A. transformation.
B. transduction.
C. conjugation.
D. replication.
conjugation
One bacterial cell passes DNA to a second cell through a sex pilus in the process of
A. transformation.
B. transduction.
C. conjugation.
D. replication.
conjugation
Which statement is true about bacteria?
A. They contain a nucleus.
B. They lack ribosomes.
C. They usually lack a cell wall.
D. They contain a single, circular DNA molecule as the genetic material.
they contain a single, circular DNA molecule as the genetic material
Which type of genetic exchange occurs among bacteria in which DNA is carried into a bacterial cell by means of a virus?
A. conjugation
B. transformation
C. transduction
D. budding
transduction
Which statement is NOT true about bacteria?
A. They lack mitochondria.
B. They lack a nucleus but contain DNA.
C. They reproduce sexually.
D. They have a single circular chromosome.
the reproduce sexually
The capsid of a virus is composed of
A. RNA.
B. protein.
C. DNA.
D. cellulose.
E. lipid.
protein
Which of the following is NOT true about viruses?
A. The genome may be DNA or RNA.
B. They contain nucleic acid, protein, and mitochondria.
C. They exhibit host specificity.
D. They are obligate intracellular parasites.
they contain nucleic acid, protein, and mitochondria
The innermost core of a virus’s structure is made up of
A. a membranous envelope.
B. either DNA or RNA.
C. a protein capsid.
D. a protein spore coat.
either DNA or RNA
A viral envelope describes:
A. the outer layer of some viruses composed of the host’s plasma membrane
B. viral DNA.
C. a prion.
D. a protein capsid.
the outer layer of some viruses composed of the host’s plasma membrane
Which of these is the most accurate description of a virus?
A. a noncellular living organism
B. one of the smallest bacteria known
C. a cell at the boundary between living and nonliving things
D. chemical complexes of RNA or DNA protected by protein
chemical complexes of RNA or DNA protected by a protein
Which of the following is considered to be acellular?
A. bacteria
B. fungi
C. algae
D. protozoans
E. viruses
viruses
The life cycle stage of an animal virus during which a mature capsid forms around copies of the viral RNA genome is
A. budding.
B. biosynthesis.
C. uncoating.
D. assembly.
assembly
Which stage of viral reproduction takes place when the spikes of the virus bind to a specific receptor molecule on the surface of a host cell?
A. attachment stage
B. penetration stage
C. biosynthesis stage
D. release stage
attachment stage
When an enveloped animal virus enters a cell during the entry stage,
A. the next thing it does is assemble a new virus.
B. the envelope is removed after the virus is inside the cell’s nucleus.
C. the protein capsid is removed through uncoating to expose the viral genome.
D. it immediately integrates its nucleic acid genome into the host chromosomes.
the protein capsid is removed through uncoating to expose the viral genome
Bovine spongiform encephalopathy (BSE), or “mad cow disease,” is caused by a(n)
A. archeon.
B. bacterium.
C. cyanobacterium.
D. prion.
E. virus.
prion