Objective Questions and Correct
Answers
What are microbes? ✅cellular, living (or nonliving/noncellular) microorganisms. Some
microbes are not microscopic; however, part of their life cycle is microscopic
What are some examples of microbes studied in microbiology? ✅living: bacteria,
archaea, fungi, protists, helminths
Nonliving: viruses and prions
What is microbiology? ✅the study of microorganisms or microbes
What are microorganisms? ✅organisms that are too small to be seen with the unaided
eye
What is a pathogen? ✅microbes that cause disease
(about 1,400 pathogens are known to infect; <1% of all microbes are pathogenic)
What is an opportunistic pathogen? ✅pathogens that cause disease only in a
weakened host
(think of this: if someone is really sick or weak, that would be the OPPORTUNE moment
for a pathogen to infect that person)
What is health care acquired infection (HAI)? ✅These infections are (literally as the
name says) acquired from health care facilities or hospitals.
Aseptic processes prevent these. They are also called nosocomial infections.
What is biogenesis? ✅Biogenesis is the theory that life comes only from other living
things. Louis Pasteur was a big proponent of showing this. He showed that it is
responsible for the propagation of life.
What does the term "normal microbiota" mean? ✅Normal microbiota includes bacteria,
archaea, and eukaryotic microbes. Certain species favor certain areas of a host. (also
called normal flora)
, What are the roles of normal microbiota? ✅Normal microbiota train our immune
system by crowding out potential pathogens, produce vitamins for us, help us digest
food, and may even impact out moods and brain function. The majority of them are
harmless.
What are the establishments of normal microbiota? ✅Data suggests that microbes
may start to colonize in us even before birth. Researchers have found low levels of
microbes in placenta and baby's first stool.
What are the disruptions of normal microbiota? ✅Normal microbiota can be disrupted
with antibiotic therapy. It kills the resident bacteria and pathogen. Reduction of normal
microbiota allows opportunistic pathogens to establish infections
What does strain mean? ✅strain is used to recognize genetic variants of the same
species. Mutations and gene transfers often lead to new strains. (they typically have a
number and/or letters after the species name)
What does parasitism mean? ✅one benefits, one is harmed (ie: host is harmed)
What does mutualism mean? ✅both organisms benefit
What does commensalism mean? ✅no perceived benefit or cost to the host
What is a biofilm? ✅sticky communities made up of single or diverse microbial species
How does a biofilm form? ✅they secrete a sticky substance that forms a protective
matrix in which the bacteria grow. Many layers tend to develop (residents of the
innermost layers are highly protected) making the infection more difficult to treat
What are the healthcare implications of biofilms? ✅NIH estimates that 60-80% of
infectious disease in humans are due to biofilm-creating microbes. Internal biofilms are
not easily managed. They are more resistant to antibiotics and are protected from
immune system
What is the goal of the aseptic technique? ✅minimize contamination from other
microbes or other areas of the body. You take a culture of a suspected microbe to figure
out what it is and how to treat it.
What elements are central to the aseptic technique? ✅sterile media, sterile
instruments, decontaminating surfaces, gloves and other protective clothing, biological
safety cabinet