SP A 4-year-old girl is rushed to the hospital with fever and a “barking” cough. She has had no childhood vaccines. Examination of her pharynx shows a “cherry-red” swollen epiglottis protruding into her airway. The etiolgoic agent is a coccobacillus. Which of the following bacteria is the most likely cause of this presentation?

In eukaryotes, during DNA replication, what are the roles of the DNA polymerases alpha (α), delta (δ), and epsilon (ε)?  

SP A 2-month- old child is rushed to the hospital with difficulty breathing and seeming “floppy.” It is thought that she contracted the etiologic agent by exposure to raw honey used to encourage her to take a formula bottle. Which of the following bacteria is most associated with this presentation?

BA Two to six hours after eating foods at a church picnic, several individuals who attended began vomiting. Half of those who had vomiting also had a watery non-bloody diarrhea. The next day most of the affected individuals were better. An epidemiologic investigation resulted in the isolation of the causative agent from a ham served at the picnic. The organism was found to be a Gram-positive coccus arranged in clusters tha is caalase positive and grew on phenyl red mannitol salt agar turning the medium bright yellow. The specific virulence factor present in this organism that is likely responsible for the gastrointestinal symptoms is:

What is an important difference between prokaryotic and eukaryotic DNA that makes eukaryotic DNA replication and gene expression much more complex?

Which amino acid does every eukaryotic protein sequence begin with?

Which of the following best describes what a riboswitch is?

Usually, in the zygote, there is global demethylation of the DNA before cells begin to differentiate. If some regions of DNA escape this demethylation, and an allele from either the mother or father is silenced, what is this called?

In terms of epigenetics, which of the following could result in a gene being expressed in heart tissue but NOT being expressed in lung tissue?

During DNA replication in prokaryotes, what mechanism allows RNA polymerase to move in just one direction toward a single replication fork, even though the leading and lagging strands are oriented on opposite directions?