Blog

Indicate the correct order of events during bacterial infections. Dissemination within the host Exposure to the pathogen Colonization and growth on the tissue Transmission to a new host Adherence to the skin/mucosa

Use the following table to answer the following questions.     A) Which organism is at the highest density cfu/ml or pfu/ml?     B) Which culture has the largest number of organisms overall?     C) In your opinion, which organism would be the toughest to kill with regards to microbial control?     D) True or False: Filtration using a .22 μm filter would remove all of these organisms (sterilize) a solution.     E) True or False: Hydrogen peroxide would be an effective chemical control agent against all of the organisms listed above       F) Choose 1 organism above and describe the cumulative dilution factor at which you would expect approximately 100 colonies or plaques.     G) Which organism could be the most difficult to accurately enumerate? Why?

Just wanted to add another apology for the Exam 1 due date issue!  This is also a reminder for me to add extra credit to ease any stress that may have occurred.  Please, please, please reach out if you have any questions, comments, concerns via email, zoom office hours meeting, etc.  I want to make SURE this did not negatively impact any of you!!! Sincerely, PW  

How quickly can antibiotic emergence arise under laboratory conditions? Describe any experiments that support your answer

Are viruses living organisms? Provide several pieces of evidence to support your answer

What are the three broad groups of viruses in the Baltimore classification system that we discussed in class?      

Where did HIV emerge in humans?  What evidence supports this hypothesis?

What amino acid sequence correctly corresponds to the following DNA sequence? This DNA sequence encodes the gyrA gene which encodes enzymes involved in DNA replication. (Fill in mRNA and AA sequences).   DNA: TAC CAT TTT AAT GTG AAA ATT mRNA: AA:     Now imagine that there was a mutation in the third position (last letter) of the fourth codon (AAT) that changed the codon from AAT -> ATT.     B) How would this affect the amino acid that would be encoded and what is the name of this mutation type?       C) How would you assess the effect of this mutation on fitness and what type of effect do you believe this change would have on a cell? (sketch out what the results would likely look like)       D) How would you assess the effect of this mutation on antibiotic resistance? What antibiotic might this cell become resistant to given the function of this protein?        

A healthy human cell produced gametes after meiosis. How many chromosomes do these gametes have?

Cystic fibrosis is a recessive condition. Two carriers, who do not have the condition, have a child. What is the probability that their child will not have this condition?