Microbiology Chapter 6 Exam Questions with 100% Correct Answers | Verified | Updated

Microbiology Chapter 6 Exam Questions with 100% Correct Answers | Verified | Updated Microbes have very narrow optimum temperature ranges. Which of the following classifications of microbes are most likely to cause human disease, based on temperature requirements? hyperthermophiles thermophiles mesophiles psychrophiles - answerMesophiles - The temperature range of mesophiles overlaps that of normal human body temperature, allowing the greatest growth. Which of the following statements accurately describes the culture media necessary for growing Clostridium tetani? A complex medium is one whose exact chemical composition is known. Nutrient agar contains ingredients that combine with oxygen and remove it, creating an anaerobic environment. A chemically defined medium is one made up of extracts such as those from yeasts, meat, or plants whose exact chemical composition may vary slightly. Reducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment. - answerReducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment. Bacteria that can grow in the presence or absence of oxygen (O2) are called __________. facultative anaerobes obligate anaerobes microaerophiles obligate aerobes - answerFacultative anaerobes - are able to use oxygen if it is present but also to grow in the absence of oxygen, although with decreased efficiency. E - answerWhich tube shows the expected growth pattern for a microaerophile? Which enzyme catalyzes the reaction: O2- + O2- + 2H+ → H2O2 + O2? superoxide dismutase oxidase catalase peroxidase - answersuperoxide dismutase The term aerotolerant anaerobe refers to an organism that: is killed by oxygen. uses oxygen or grows without oxygen. requires more oxygen than is present in air. requires less oxygen than is present in air. does not use oxygen but tolerates it. - answerdoes not use oxygen but tolerates it. A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called a(n) selective medium. differential medium. enrichment culture. selective and differential medium. differential and enrichment culture. - answerselective and differential medium. A culture medium consisting of agar, peptone, and beef heart is a reducing medium. selective medium. chemically defined medium. differential medium. complex medium. - answercomplex medium. Through metabolism, pathogens often produce acids that interfere with their own growth. __________ are/is added to media to control pH changes. Salts pH indicators Buffers Growth inhibitors Oxygen - answerBuffers An organism that you are studying gro