Microbes in Household & Industrial Products NEET Questions with Answers

Microbes in Household and Industrial Products is a high-yield topic for NEET Biology. Questions are often based on the direct NCERT examples of microorganisms, products and their applications.

This practice guide covers important NEET-style questions on curd, bread, cheese, organic acids, alcoholic beverages, antibiotics and microbial products.

NEET Strategy: Do not memorize the microorganisms randomly. Learn them as a three-part combination: Microbe → Product → Application.

Question 1: Match the Microorganisms with Their Products

Consider the following microorganisms and products:

Lactobacillus
Saccharomyces cerevisiae
Aspergillus niger
Acetobacter aceti

Match them with:

Cheese
Curd
Citric acid
Bread
Acetic acid

Answer

The correct matching is:

Microorganism	Product
Lactobacillus	Curd
Saccharomyces cerevisiae	Bread
Aspergillus niger	Citric acid
Acetobacter aceti	Acetic acid

Correct option: 2

Explanation

Lactobacillus converts milk into curd through lactic acid fermentation.

Saccharomyces cerevisiae, or baker's yeast, is used in bread making.

Aspergillus niger is an important microbial source of citric acid.

Acetobacter aceti is associated with the production of acetic acid.

Memory Trick:
Lacto → Milk/Curd
Saccharomyces → Bread
Aspergillus niger → Citric acid
Acetobacter → Acetic acid

Question 2: Nutritional Value of Curd

Conversion of milk into curd improves its nutritional value by increasing the amount of which vitamin?

Vitamin D
Vitamin A
Vitamin E
Vitamin B₁₂

Answer

Correct answer: Vitamin B₁₂

Explanation

Lactic acid bacteria such as Lactobacillus grow in milk and help convert it into curd. According to NCERT, curd is more nutritious than milk because it contains a number of vitamins, especially vitamin B₁₂.

NEET Point: Milk → Curd by LAB → Increased nutritional value, especially Vitamin B₁₂.

Question 3: Alcoholic Beverage Without Distillation

Which of the following alcoholic beverages is produced without distillation?

Wine
Whisky
Rum
Brandy

Answer

Correct answer: Wine

Explanation

Yeast such as Saccharomyces cerevisiae is used for alcoholic fermentation. Wine is produced through fermentation without the distillation step used for distilled alcoholic beverages.

Whisky, rum and brandy are examples of distilled alcoholic beverages.

Remember: Fermentation produces alcohol; distillation is a subsequent process used for certain alcoholic beverages to increase alcohol concentration.

Question 4: Discovery of Penicillin

How was penicillin discovered?

Answer

Penicillin was discovered by Alexander Fleming in 1928.

Fleming observed that a mould growing accidentally on a bacterial culture plate produced a substance that inhibited the growth of bacteria around it.

The mould was identified as belonging to the genus Penicillium, and the antibacterial substance was named penicillin.

Important NCERT Microbe-Product Questions

The following combinations are especially important for NEET revision:

Microorganism	Product / Use
Lactobacillus	Curd / Lactic acid
Saccharomyces cerevisiae	Bread / Alcoholic fermentation
Propionibacterium shermanii	Swiss cheese
Penicillium roqueforti	Roquefort cheese
Aspergillus niger	Citric acid
Acetobacter aceti	Acetic acid
Penicillium	Penicillin
Streptomyces griseus	Streptomycin
Trichoderma polysporum	Cyclosporin A
Monascus purpureus	Statins

NEET Memory Map

Curd → Lactobacillus
Bread → Saccharomyces cerevisiae
Swiss cheese → Propionibacterium shermanii
Roquefort cheese → Penicillium roqueforti
Citric acid → Aspergillus niger
Acetic acid → Acetobacter aceti
Penicillin → Penicillium
Streptomycin → Streptomyces griseus
Cyclosporin A → Trichoderma polysporum
Statins → Monascus purpureus

Try Yourself: 5 NEET-Style Questions

Q1. Which microorganism is most closely associated with bread making?

Lactobacillus
Saccharomyces cerevisiae
Acetobacter aceti
Aspergillus niger

Answer: 2. Saccharomyces cerevisiae

Q2. Citric acid is commercially produced using:

Aspergillus niger
Monascus purpureus
Streptomyces griseus
Trichoderma polysporum

Answer: 1. Aspergillus niger

Q3. Which microorganism is associated with Swiss cheese?

Penicillium roqueforti
Propionibacterium shermanii
Lactobacillus
Acetobacter aceti

Answer: 2. Propionibacterium shermanii

Q4. Which microbial product is used as an immunosuppressive agent?

Statin
Penicillin
Cyclosporin A
Citric acid

Answer: 3. Cyclosporin A

Q5. Statins are associated with:

Monascus purpureus
Aspergillus niger
Streptomyces griseus
Saccharomyces cerevisiae

Answer: 1. Monascus purpureus

Common NEET Traps

Do not confuse Aspergillus niger with Acetobacter aceti.
Citric acid → Aspergillus niger.
Acetic acid → Acetobacter aceti.
Curd → Lactobacillus.
Bread → Saccharomyces cerevisiae.
Swiss cheese → Propionibacterium shermanii.
Roquefort cheese → Penicillium roqueforti.
Cyclosporin A → Trichoderma polysporum.
Statins → Monascus purpureus.

Frequently Asked Questions

Which vitamin increases when milk is converted into curd?

According to NCERT, curd contains increased amounts of vitamins, especially vitamin B₁₂.

Which microorganism is used in curd formation?

Lactobacillus, a lactic acid bacterium, plays an important role in curd formation.

Which alcoholic beverage is produced without distillation?

Wine is produced through fermentation without the distillation step used for beverages such as whisky, rum and brandy.

Who discovered penicillin?

Alexander Fleming discovered penicillin in 1928 after observing antibacterial activity associated with a Penicillium mould.

Which microbe produces citric acid?

Aspergillus niger is an important microbial source of citric acid.

Final Takeaway

Questions from this chapter are often direct but can become confusing when similar-looking microbial names are mixed together.

The safest NEET strategy is to repeatedly revise the microorganism → product → application combinations and practice matching questions.

Master the NCERT examples first. Then use PYQs to test your recall.