Class 12 Biology Notes

Chapter: Microbes in Human Welfare

Chapter Summary

Microbes in Human Welfare explains the beneficial roles of microorganisms in human life. They are used in household food products like curd, cheese, bread, and beverages. In industrial production, microbes help in antibiotics, enzymes, and organic acid formation. In sewage treatment and biogas production, microbes ensure waste management and energy recovery. They also act as biofertilizers and biocontrol agents, improving agriculture sustainably.

50 Questions and Answers

Penicillium notatum produces penicillin.

Saccharomyces cerevisiae (yeast).

Lactobacillus bacteria.

Activated sludge bacteria and methanogens.

Trichoderma fungi.

Propionibacterium shermanii.

Streptomycin.

Acetobacter aceti.

Aspergillus niger.

Methane (biogas).

Rhizobium.

Lactobacillus.

Yeast (Saccharomyces).

Penicillin.

Methanogens (Methanobacterium).

Methanobacterium.

Aspergillus (amylase), Streptococcus (streptokinase).

Clostridium butylicum.

Saccharomyces cerevisiae.

Azolla-Anabaena symbiosis.

Cephalosporin.

Aspergillus niger (citric acid).

Spirulina.

Trichoderma polysporum.

Trichoderma (cyclosporin A).

Bacillus thuringiensis (Bt toxin).

Heterotrophic aerobic bacteria.

Anaerobic bacteria.

Bacillus thuringiensis.

Acetobacter aceti.

Aspergillus niger.

Gentamicin.

Mushrooms (Agaricus).

Spirulina.

Pseudomonas denitrificans.

Nitrosomonas and Nitrobacter.

Pseudomonas.

Aspergillus oryzae.

Clostridium acetobutylicum.

Streptomyces erythraeus.

Clostridium.

Rhizobium.

Azotobacter.

Blue-green algae (Anabaena, Nostoc).

Acetobacter aceti.

Lactobacillus and Bifidobacterium.

Saccharomyces cerevisiae.

Propionibacterium.

Bacitracin.

Because they provide food, medicines, energy, soil fertility, waste management, and disease control essential for human welfare.