Microbio Past Tests

which of the following domains contain microbes? select all that apply

• bacteria

• archaea

• eukarya

which of the following represents the correct way to type a binomial (gnus and species) scientific name?

Clostridium difficile

which of the following lists the taxonomic heirarchy in the correct order, starting from most broad classification?

domain, kingdom, phylum, class, order, family, genus, species

infections of the bacterium Pseudomonas aerginosa are uncommon in healthy adults, but relatively frequent in individuals with cystic fibrosis. in reference to its relationship with a human host, which of the following best describes Pseudomonas aerginosa in relationship to the human host?

opportunistic pathogen

nuclear medicine is a medical specialty that uses radioactive isotopes of chemical elements as tools to diagnose or treat diseases. what are isotopes?

atoms of the same element that differ in their # of neutrons

a patient in your care comes in with gastrointestinal infection leading to severe repeated vomiting. when you perform a blood draw and subsequent testing, their blood pH comes back as 7.6. compared to the typical range of 7.35-7.45, which of the following correctly describes this patient’s blood pH?

basic

atoms in lipid fatty acid tails are linked by nonpolar covalent bonds. this suggests that the atoms do which of the following?

share electrons, with both atoms having approximately the same pull for the shared electrons

RNA has both similarities to, and differences from, DNA. which of the below correctly articulate differences between these molecules? select two asnwers

• RNA usually functions as a single-stranded molecule; DNA is usually double stranded

• in RNA, one of the four nitrogenous bases is uracil, while in DNA the comparable base is thymine

a researcher is studying how Saccharomyces cerevisiae (baker’s yeast) responds to nutrient availability. she finds that when glucose is abundant, yeast cells reduce production of enzymes needed to break down other sugars. further studies suggest that years must be using post-transcriptional methods to change gene expression. which of the following might be the mechanism of regulation in Saccharomyces cerevisiae?

structural changes in the enzyme’s mRNA riboswitch that lead to decreased translation

large protein biomolecules are formed by the generation of ___ bonds (a type of covalent bond) between adjacent amino acids. this process is called translation and is catalyzed by an enzyme called the ___

peptide; ribosome

in a DNA double helix, two linear nucleotide strands are linked by ___ bonds between their nitrogenous bases. compared to the bonds in linking nitrogenous base ‘rungs’, the bonds between adjacent nucleotides’ sugar and phosphate groups, which make up the ‘side rails’ or backbone of the DNA, are ___

hydrogen; stronger

an organism’s set of observable traits, or ___, is influenced by both genetic content (aka their ___) and the environment

phenotype; genotype

the ___ of genes in a cell’s genome are expressed at any given time. the expression of ___ genes is induced in response to specific stimuli so that microbes can respond to changing environments

minority; repressed

the process of DNA replication uses the information found in ___ to synthesize new ___. the enzyme responsible for catalyzing the formation of covalent bonds in the growing polymer is ___

DNA; RNA; DNA polymerase

prokaryotic and eukaryotic ribosomes share which of the following features? select all that apply

• composed of protein and rRNA

• catalyze the process of translation

however, prokaryotic and eukaryotic ribosomes are slightly different. compared to eukaryotic ribosomes, bacterial ribosomes are which of the following?

smaller

a patient with symptoms of severe gastrointestinal distress. bacterial and viral pathogens are ruled out. microscopy of the patient’s stool reveals a single-celled organism which moves using the coordinated action of many short, hair-like appendages. the most likely-cause of the infection is

Balantidium coli, a ciliated protozoan

cells must intake nutrients to generate energy for gene expression, protein production, enzyme function, and cellular upkeep. which of the following would be the best option for a new antimicrobial drug that could selectively interfere with nutrient intake in protozoa but not in commensal bacteria?

***

which of the following structures does not help bacteria adhere to surfaces?

***

tinea, or ringworm infections, are caused by

fungi

compared to macronutrients, micronutrients are

present in smaller quantities in organisms

all viruses encode instructions in a nucleic acid genome (DNA or RNA). on average, viruses with RNA genomes evolve ___ than viruses with DNA genomes

faster

from a murky pond water sample, you isolate a microscopic organism that you can’t identify from comparison to existing scientific textbooks or databases. the new microbe is made up of relatively large cells that contain obvious nuclei. the organism is multicellular, generates hyphae at certain growth temperatures, has a cell wall made of chitin, and has relatively high concentrations of ergosterol in its plasma membrane. this organism should be classified in the ___ kingdom

fungi

prokaryotes reproduce asexually through a process called ___ ___. in eukaryotes, asexual cellular reproduction is called ___, while the cell division process used to form gametes for sexual reproduction is called ___

binary fission; mitosis; meiosis

plant

plants and photosynthetic microbes harvest energy from the sun to generate ATP, and are also able to ‘fix’ inorganic carbon to organic forms. these organisms are best described as ___. however, most human-infecting microbes generate energy and obtain organic carbon from the consumption of biologically derived molecules, so they are called ___

phototrophs; ***

although there is considerable variation among different viruses, all virions consists of at least a ___, made of nucleic acid, and a ___, made of protein

genome; ***

through the process of generalized transduction, a bacteriophage horizontally transfers genes encoding an efflux pump from bacterium 1 to bacterium 2. assuming bacterium 2 successfully expresses the efflux pump genes, it likely becomes ___ susceptible to antibiotics than it was before

less

you are treating a patient with severe recurring diarrhea, so you collect and send a stool sample to the clinical microbiology lab. the resulting report lists Clostridia difficile as a potential etiological agent of disease. Clostridia infections are particularly problematic to treat in part because members of this genus of bacterium can form ___

***

i discover a new fungus that morphs from filamentous to yeast-like at 37degree C/98 degreesF. the term used to describe fungi that can transition between filamentous and yeast-like forms is ___. this often gets confused with the term ___, which is used to describe bacteria which can adopt different shapes under different conditions.

***; pleiomorphic

the term used to describe fungal infections in human beings is ___. the majority of clinical cases of fungal infections are in i’ll or immunocompromised patients, meaning that most fungi are ___ (term to describe organisms that don’t cause disease in healthy, immunocompetent individuals)

mycoses; ***