chapter 28 Flashcards
microbiology is the study of microbes. these include all but which of the following?
plants
what general feature is necessary to consider an organism a microbe?
small enough that a microscope is required to see them
millers’ laboratory experiments showed that
the primitive gases 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?
oxygen (O2)
considering the various theories, the energy used in forming organic molecules in the primitive atmosphere could have come from all EXCEPT
sound
what is the evolutionary relationship among archaea, bacteria, and eukarya?
archaea and eukarya share nucleic acid similarities, so eukarya split off from archaea
a new classification by domains separates prokaryotes into
archaea and bacteria
one bacterial cell passes DNA to a second cell through a sex pilus in the process of
conjugation
bacterial cells pick up free pieces of DNA from the medium pieces that were released from dead bacteria in a process called
transformation
which of these is a correct description of a form of horizontal gene transfer in bacteria?
conjugation occurs when a cell passes DNA to another cell by means of a sex pilus
which type of genetic exchange occurs among bacteria in which DNA is carried into a bacteria cell by means of a virus?
transduction
which statement is true about bacteria?
they contain a single, circular DNA molecule as the genetic material
which statement is NOT true about bacteria?
they reproduce sexually
the capsid of a virus is composed of
protein
which of the following is NOT true about viruses?
they contain nucleic acid, protein, and mitochondria
the innermost core of a virus’ structure is made up of
either DNA or RNA
a viral envelope describes
the outer layer of some viruses composed of the host’s plasma membrane
which of these is the most accurate description of a virus?
chemical complexes of RNA or DNA protected by protein
which of the following is considered to be acellular?
viruses
the life cycle stage of an animal virus during which a mature capsid forms around copies of the viral RNA genome is
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?
attachment stage
when an enveloped animal virus enters a cell during the entry stage
the protein capsid is removed through uncoating to expose the viral genome
bovine spongiform encephalopathy (BSE), or “mad cow disease,” is caused by a
prion
some human diseases appear to be due to protein agents that may convert other normal proteins in the cell to also become these agents. this new disease protein agent is called a
prion
who invented the term “virus”?
Louis Pasteur
cyanobacteria
does photosynthesis similar to green plants
the process of bacterial reproduction is referred to as
binary fission
the first membranes that formed before full cells were likely made of
fatty acids
which type of archaen is likely to be found in the intestines of animals
methanogen
Antonie van Leeuwenhoek
improved microscope lenses to allow him to see tiny organisms he called animalcules
Louis Pasteur
did experiments to refute the concept of spontaneous generation
