This set of Microbiology Multiple Choice Questions & Answers (MCQs) focuses on “World of Bacteria I – Facultatively Anaerobic Gram – Negative Rods”.
1. The cell diameter of bacteria belonging to family Enterobacteriaceae is ____________
a) 1 m
b) 1 cm
c) .3-1.5 micrometre
d) 5 micrometer
Explanation: A distinctive feature of the family Enterobacteriaceae is that the cell diameter is 0.3 to 1.5 micrometers.
2. What is the cell shape of the organisms belonging to the family Enterobacteriaceae?
d) straight rod
Explanation: The cell shape of organisms belonging to the family Enterobacteriaceae is that of a straight rod.
3. Enterobacteriaceae possesses endoflagella.
Explanation: Enterobacteriaceae possesses lateral flagella and moves by means of it. It does not possess endoflagella.
4. Which of the following genus of bacteria causes gastroenteritis in humans?
Explanation: Some bacteria of genus Escherichia causes gastroenteritis and some others can also cause urinary tract infections.
5. Enterobacter sp. gives negative result for Voges-Proskauer test.
Explanation: Enterobacter sp. gives positive results for Voges-Proskauer test by giving a reddish-pink colouration.
6. Which of the following genus of bacteria under the family Enterobacteriaceae is mainly associated with plants?
Explanation: Bacteria belonging to the genus Erwinia differ from most other Enterobacteriaceae by being mainly associated with plants. They are often plant pathogens, causing diseases such as blights, leaf spot, wilts, etc.
7. Which of the following is the causative agent of the plague?
Explanation: Yersiniae are parasites of animals but can also cause infections in humans. For example, Y.pestis is the causative agent of the plague.
8. The family Vibrionaceae is _________________
c) coccus shaped
Explanation: A distinctive feature of the family Vibrionaceae is that they are usually oxidase-positive. They are motile by means of polar flagella and cell shape is that of curved or straight rods.
9. Which of the following genus shows the characteristic of bioluminescence?
Explanation: Some species of genus Vibrio can emit light of a blue-green color(bioluminescence), an oxygen-dependent reaction catalyzed by the enzyme luciferase.
10. Among the given families, which family contains organisms that are non-motile?
Explanation: Pasteurellaceae contains cells that are nonmotile. Their cell diameter is very small and the shape is that of a straight rod.
11. The X factor and/or the V factor is required by which genus of bacteria?
Explanation: Haemophilus bacteria is distinguished by unusual nutritional requirements: the X factor (heme, occurring in blood) and/or the V factor(the coenzyme nicotinamide adenine dinucleotide).
Sanfoundry Global Education & Learning Series – Microbiology.
To practice all areas of Microbiology, here is complete set of 1000+ Multiple Choice Questions and Answers.