The surgical equipment used during a craniectomy is sterilized using pressurized steam at 121°C for 15 minutes. Reuse of these instruments can cause transmission of which of the following pathogens?
ANon-enveloped viruses
BSporulating bacteria
CPrions
DEnveloped viruses
EYeasts
A codon is an mRNA sequence consisting of 3 nucleotides that codes for an amino acid. Each position can be made up of any 4 nucleotides (A, U, G, C); therefore, there are a total of 64 (4 x 4 x 4) different codons that can be created but they only code for 20 amino acids. This is explained by the wobble phenomenon. One codon for leucine is CUU, which of the following can be another codon coding for leucine?
ACUA
BCCC
CUAA
DCCA
EAUG
An outbreak of diphtheria has occurred for the third time in a decade in a small village in South Africa. Diphtheria is endemic to the area with many healthy villagers colonized with different bacterial strains. Vaccine distribution in this area is difficult due to treacherous terrain. A team of doctors is sent to the region to conduct a health campaign. Toxigenic strains of C. diphtheria are isolated from symptomatic patients. Which of the following best explains the initial emergence of a pathogenic strain causing such outbreaks?
AInfection with a lytic phage
BConjugation between the toxigenic and non-toxigenic strains of C. diphtheriae
CSuppression of lysogenic cycle
DLysogenic conversion
EPresence of naked DNA in the environment
+ 7 more in the PDF
Browse all chapters