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Prokaryotic Cells

Microbiology Questions on Competency, Lysogeny & Dilution

1. Define natural competency? 2. What is a serial dilution? 3 True or False. You can use plaque assay to determine the number of a lysogenic phage? 4. Can a spectrophotometer be used to measure viable counts of bacteria in culture? 5. Is transmittance or absorbance directly related to the concentration particles pr

Transformation and competent cells

1. If you spread 0.1 ml of 10-3 of a sewage sample on a plate, and obtained 221 colonies on the plate after incubation, how many CFU/ml were present in the undiluted sewage sample? Please show work 2. How can you make E.coli cells competent so that they can be transformed? 3. What is the appearance of transformed bacteria

Microbiology Study Questions

1. Describe how DNA serves as genetic information. 2. Describe the process of DNA replication. 3. Describe protein synthesis, including transcription, RNA processing, and translation. 4. Explain the regulation of gene expression in bacteria by induction, repression, feedback inhibition, and catabolic

Microbiology Study Questions

1. Clostridium and Streptococcus are both catalase-negative. Streptococcus grows by fermentation. Why is Clostridium killed by oxygen, whereas Streptococcus is not? 2. Assume that after washing your hands, you leave ten bacteria cells on a new bar of soap. You then decide to do a plate count of the soap after it was left in

Microbiology Questions

1. How did the theory of biogenesis lead the way for the germ theory of disease? 2. The antibiotic amphotericin B causes leaks in cells by combining with sterols in the plasma membrane. Would you expect to use amphotericin B against a bacterial infection? A fungal infection? Offer a reason why amphotericin B has severe side

Microbiology Questions

Please help with the attached micro questions. Several questions have not been answered as I cannot find anything referring to the topic in my text. 1. Passive immunity can a. Involved an injection of antibodies b. Be acquired by a child from its mother c. Be administered with a convalescent serum d. All the above are cor

Microbiology questions

Please confirm correctness of answers to the attached questions. 2. The diagnosis of tuberculosis is aided by a. Observation of cells with bipolar staining in the blood. b. Recovery of acid fast rods from the sputum. c. A skin rash on the palms and soles. d. A positive Weil-Felix test. 22. A child suffering from re

Why do streptococcus bacteria grow slowly?

I would like to know why streptococcus bacteria grow slowly. I know that they use anearobic respiration and produce small amounts of ATP as a result. Most of the energy goes into the end product, lactic acid, and this probably accounts for some of their slow growth. But I am not sure that this is the complete explanation. I

Spicy Inhibitors Anti-Microbial Properties

1) If you lived in a tropical region of India without refrigeration, which spice would you use most often in your cooking and WHY? 2) Which spice (Black Pepper Agar, Chili Powder Agar, Cloves Agar) would be least effective in controlling microbial growth of Saccharomyces cerevisiae? WHY? 3) Why would spices have anti-mic


Some species of bacteria that live at the surface of sediment on the bottom of lakes are facultative anaerobes; that is, they are capable of either aerobic or anaerobic respiration. How will their metabolism change during the summer when the deep water becomes anoxic (deoxygenated)? If the bacteria continue to grow at the same

Food Microbiology: Pasteurization

1. What the last definition of pasteurization according to FDA (2005). 2. List 20 antimicrobials used in food manufacturing and specify the maximum allowance of each one in food. 3. What are bacteriocins, list 5 of them and provide examples of applications in foods. 4. List 5 natural antimicrobials us

E. coli; Amino Acid Alanine; Carcinogen; Mutagen ... etc

Subject: There is a strain of E. coli that is unable to make its own amino acid alanine. I am answering practice questions at the end of the chapter to get ready for a test. This is a senario given that if I allow this bacterial strain to grow in medium containing alanine and then plate 10 to the 6th power cells on a petri

General Microbiology (Bacteria, Energy Production, DNA etc.)

A number of multiple choice Microbio questions. Examples: #1 Compare and contrast carbohydrate catabolism and energy production in the following bacteria: a. Pseudomonas, an aerobic chemoheterotroph b. Spirulina, an oxygenic photoautotroph c. Ectothiorhodospira, an anoxygenic photoautotroph #2 The bacterial enzyme str

Botulism in a Hospital

40-year-old man admitted into Hospital. He has a splitting headache, his legs were unsteady, and his vision was blurred. During the examination, it was obvious that something was wrong wit his throat. The throat was not sore, but it felt stiff and tight, and it was almost impossible for him to speak. Over the next 7 days, 28

Need help with the questions below

1) What are three reasons one might a situation in which bacterial colonies are found on the first section of a streak plate, but not on sections two and three? 2) How would one determine which colonies might be contaminants on a streak plate?

Prokaryotes into archaebacteria and eubacteria

My question is in reference to the further classification of prokaryotes into archaebacteria and eubacteria. The textbook did not clearly mention why these two "lineages" are distinguished except for the fact that archaebacteria can live in extreme environmental conditions. I am wondering what is the distinction between the

Diluting bacterial cultures.

You have a bacterial culture with a concentration of 3.4 x 10^9 cells/ml. If you dilute the culture 10^-8, what would be the final concentration? If you then plate 1 ml of the culture, how many colonies would you expect?

Working with serial dilutions.

You performed the following dilution series on a culture of Escherichia coli: 1 ml of the original culture to 99 ml broth then 1 ml cell suspension to 9 ml broth then 2 ml to 8 ml broth then 0.1 ml to a culture plate The next day, you count 52 colonies on the plate. What was the concentration of the original culture?

Discussing Vaccine Types

What kind of vaccine (live, dead, whole, viral protein, etc) would be the best for a virus that causes a mild disease in individuals with a heavy cytolytic response and severe to individuals who produced a primarily antibody response? Ideas are generated.