Microbes in Human Welfare Practice Questions
Class 12 · Biology · 2907 free MCQs with instant results and detailed explanations.
2907
Total
884
Easy
1434
Medium
589
Hard
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Topics in Microbes in Human Welfare
Biogas
728
Industrial Products
711
Biocontrol and Biofertilizers
738
Microbes in Food
730
Sample Questions from Microbes in Human Welfare
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
Which of the following microorganisms is primarily used in the production of yogurt?
A.
Lactobacillus bulgaricus
B.
Saccharomyces cerevisiae
C.
Escherichia coli
D.
Streptococcus pneumoniae
Show Answer & Explanation
Correct Answer: A
Lactobacillus bulgaricus is a bacterium that ferments lactose into lactic acid, an essential step in yogurt production.
Q2
Easy
Fermentation is a process that converts sugars into acids, gases, or alcohol. Which of the following foods is produced by alcoholic fermentation?
A.
Bread
B.
Sauerkraut
C.
Cheese
D.
Pickles
Show Answer & Explanation
Correct Answer: A
Bread production involves the fermentation of sugars by yeast, resulting in the release of carbon dioxide, which helps the dough rise.
Q3
Easy
Which type of fermentation is primarily used in the production of vinegar?
A.
Lactic Acid Fermentation
B.
Alcoholic Fermentation
C.
Acetic Acid Fermentation
D.
Butyric Acid Fermentation
Show Answer & Explanation
Correct Answer: C
Acetic Acid Fermentation involves the conversion of alcohol into acetic acid by acetic acid bacteria, leading to vinegar production.
Q4
Medium
Which microbe is primarily responsible for the fermentation of yogurt?
A.
Lactobacillus bulgaricus
B.
Escherichia coli
C.
Bifidobacterium bifidum
D.
Staphylococcus aureus
Show Answer & Explanation
Correct Answer: A
Lactobacillus bulgaricus is a lactic acid bacterium essential for yogurt fermentation.
Q5
Medium
What is the role of Saccharomyces cerevisiae in baking?
A.
Preserving bread
B.
Raising bread
C.
Flavoring bread
D.
Coloring bread
Show Answer & Explanation
Correct Answer: B
Saccharomyces cerevisiae, or baker's yeast, ferments sugars to produce carbon dioxide, causing the dough to rise.
Q6
Medium
Which of the following bacteria is used in the production of vinegar?
A.
Lactobacillus
B.
Acetobacter
C.
Bacillus
D.
Clostridium
Show Answer & Explanation
Correct Answer: B
Acetobacter bacteria convert alcohol into acetic acid, thus producing vinegar.
Q7
Medium
What is the primary commercial use of the fungus Aspergillus oryzae?
A.
Bread making
B.
Soy sauce production
C.
Beer brewing
D.
Wine fermentation
Show Answer & Explanation
Correct Answer: B
Aspergillus oryzae is used in the fermentation of soybeans to produce soy sauce.
Q8
Hard
Which of the following bacteria is primarily used in the production of yogurt?
A.
Lactobacillus bulgaricus
B.
Streptococcus thermophilus
C.
Escherichia coli
D.
Bacillus subtilis
Show Answer & Explanation
Correct Answer: A
Lactobacillus bulgaricus is a key bacterium in yogurt production as it ferments lactose into lactic acid, contributing to yogurt's texture and flavor.
Q9
Hard
Which microbial process is responsible for the production of vinegar?
A.
Fermentation
B.
Nitrification
C.
Sulfurization
D.
Oxidation
Show Answer & Explanation
Correct Answer: A
Vinegar production involves the fermentation of ethanol by acetic acid bacteria, leading to the formation of acetic acid, the main component of vinegar.
Q10
Hard
Which of the following is NOT a product of yeast fermentation?
A.
Ethanol
B.
Carbon dioxide
C.
Lactic acid
D.
Glycerol
Show Answer & Explanation
Correct Answer: C
Lactic acid is produced by lactic acid bacteria, not yeast. Yeast primarily ferments sugars to produce ethanol and carbon dioxide.
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Microbes in Human Welfare — Class 12 Biology Practice Questions Online
This page contains 2907 practice MCQs for the chapter Microbes in Human Welfare in Class 12 Biology. The questions are organized by difficulty — 884 easy, 1434 medium, 589 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 4 topics, giving you comprehensive coverage of the entire chapter.