This set of Microbiology Multiple Choice Questions & Answers (MCQs) focuses on “Cultural Characteristics”.
1. The National Collection of Type Cultures is situated in ____________
Explanation: In England, the National Collection of Type Culture is in London which is a large central collection whose main purpose would be the acquisition, preservation, and distribution of authentic cultures of living organisms.
2. The American Type Culture Collection, located in Rockville, Maryland in the year 1980 has a collection of bacterial strain in what numbers?
Explanation: In US the major collection is the American Type Culture Collection, located in Rockville, Maryland. In 1980 the collection included the following number of strains: bacteria-11,500; bacteriophages-300; algae-130; protozoa-720; fungi and fungal viruses-13700 etc.
3. Which of the following has a larger diameter?
a) well-separated colonies
b) crowded colonies
c) young colonies
d) old colonies
Explanation: Well-separated colonies have a larger diameter than those which are crowded together because widely separated colonies are subject to less competition for nutrients and less inhibition by toxic products of metabolism.
4. Surface texture of strains are related to virulence.
Explanation: For several species of pathogenic species, the surface texture of colonies may bear a relation to virulence. For example, Smooth colonies of S.pneumoniae or of Salmonella species are usually virulent, whereas Rough colonies are not.
5. What is the color of colonies of Staphylococcus aureus?
Explanation: Staphylococcus aureus produces and retains water-insoluble pigments which give golden color to their colonies.
6. Pyoverdin is which type of pigment?
a) water-insoluble pigment
b) water-soluble pigment
c) fluorescent pigment
d) sparingly water-soluble pigment
Explanation: Pyoverdin is a fluorescent pigment and is water-soluble in which the agar medium around the colonies glows white or blue-green when exposed to ultraviolet light. It is produced by P.aeruginosa.
7. Growth in broth cultures occurs mainly in the form of __________
a) slightly turbid
b) heavy surface pellicle
Explanation: Growth in broth cultures occurs mainly in the form of a heavy surface pellicle and the medium below the pellicle is only slightly turbid.
8. Which bacteria among the following produces a water-insoluble pigment?
a) Mycobacterium kansasii
b) Pseudomonas aeruginosa
c) Chromobacterium violaceum
d) Pseudomonas chlororaphis
Explanation: Chromobacterium violaceum produces a water-insoluble pigment which causes its colonies to become violet in color.
Sanfoundry Global Education & Learning Series – Microbiology.
To practice all areas of Microbiology, here is complete set of 1000+ Multiple Choice Questions and Answers.