🦠 Microbiology Solved MCQs with Answers

Practice 1927 approved 🦠 Microbiology questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1927 solved MCQs

The botulism intoxication occurs due toAnswer: neurotoxin The Bacillus cereus causes gasteroenteritis by the production of an exoenterotoxin which is released in food as a result ofAnswer: cell autolysis Staphylococcal intoxication is caused by the toxin m the food fromAnswer: Staphylococcus aureus The most important organism involved in manufacture of Koji isAnswer: both (a) and (b) The most commonly used medium for the build up of cultures and the production of baker's yeast consist ofAnswer: molasses, minerals and salts The manufacture of baker's yeast involveAnswer: S. cerevisiae Which of the following organism is found at the initial stages in the batter of Idli?Answer: Leuconostoc mesentroides Grains spoiled by molds are a potential animal or human health hazard as well as a great economic loss. Which is/are the common species of molds in the spoilage of stored grains by molds?Answer: All of these Ropiness in bread is caused byAnswer: Bacillus subtilis Which of the following (s) is/are the major spoilage of soft drinks from the marked growth of yeasts and bacteria?Answer: Cloudiness and ropiness Mined salt has been reported to contain aboutAnswer: 70% Micrococcus, 20% Coryneforms and 4% Bacillus Which of the following strain(s), that grow in the jellies and candid fruits, are able to grow in sugar concentration upto 67.5%?Answer: All of these The immediate source of the flat sour bacteria is usually theAnswer: plant equipment The ability of B. coagulans to grow in tomato juice depends upon theAnswer: all of these Flat sour spoilage of acid foods is caused byAnswer: B. coagulans The most important kind of chemical spoilage of canned foods is the hydrogen swell which is favored byAnswer: all of these The presence of viable non-spore forming bacteria in heat process canned foods indicates leakage of the container. Which of the following is responsible for the spoilage of leaky cans?Answer: Cooling water Sulfur stinker spoilage, caused by is uncommonly found inAnswer: Low acid foods Medium acid foods with a pH between 5.3 and 4.5 are likely to undergoAnswer: TA spoilage Canned sweetened condensed milk may become thickened byAnswer: Saccharomyces species The canned acid foods such as pineapple, tomatoes and pears have been found spoiled by C. pasteurianum. Such spoilage is more likely when the pH of the food isAnswer: >4.5 Which of the following species can cause bitterness, acidity and curdling in canned milk, cream and evaporated milk?Answer: Bacillus Acid foods with a pH between 4.5 and 3.7 usually are spoiled byAnswer: both (a) and (b) The butyric acid type of fermentation in acid or medium acid foods, with swelling of the container by the carbon dioxide and hydrogen gas is caused byAnswer: both (a) and (b) Which of the following(s) is/are porteolytic or putrefactive decomposing proteins with the production of malodorous compounds such as H2S, mercaptans, ammonia, indole and skatole?Answer: both (a) and (b) Canned poultry is more often spoiled byAnswer: putrefactive than by Saccharolytic Clostridia Canned meat and fish exhibit spoilage byAnswer: Both (a) and (b) High acid foods with a pH < 3.7 undergo spoilage byAnswer: do not undergo spoilage by microorganisms The putrifactive anaerobes grow best in theAnswer: low acid canned foods High acid foods with a pH above 5.3 are especially subjected toAnswer: Both (a) and (b)