Biogas is a mixture of gases containing predominantly:

[Microbes-in-Human-Welfare] [class-xii ]

• Hydrogen
• Carbon Dioxide
• Nitrogen
• Methane
Correct Option: D  [ Methane ]

Remark: Biogas is a mixture of gases containing predominantly methane, produced by microbial activity.

The common gas produced during fermentation processes cited in cheesemaking, dough preparation, and beverage production is:

[Microbes-in-Human-Welfare] [class-xii ]

• Methane
• Hydrogen Sulphide
• Carbon Monoxide
• CO2
Correct Option: D  [ CO2 ]

Remark: In the examples cited in relation to fermentation of dough, cheese making and production of beverages, the main gas produced was CO2.

The group of bacteria that grow anaerobically on cellulosic material and produce large amounts of methane are collectively called:

[Microbes-in-Human-Welfare] [class-xii ]

• Actinomycetes
• Methanogens
• Cyanobacteria
• Pectinases
Correct Option: B  [ Methanogens ]

Remark: Certain bacteria, which grow anaerobically on cellulosic material, produce large amount of methane along with CO2 and H2. These bacteria are collectively called methanogens.

An example of a common methanobacterium is:

[Microbes-in-Human-Welfare] [class-xii ]

• Azotobacter
• Methanobacterium
• Bacillus thuringiensis
• Trichoderma polysporum
Correct Option: B  [ Methanobacterium ]

Remark: One such common bacterium that is a methanogen is Methanobacterium.

Methanogens are commonly found in the anaerobic sludge during sewage treatment and also in which specific anatomical part of cattle?

[Microbes-in-Human-Welfare] [class-xii ]

• Intestines
• Kidney
• Rumen (a part of stomach)
• Lungs
Correct Option: C  [ Rumen (a part of stomach) ]

Remark: These bacteria are commonly found in the anaerobic sludge during sewage treatment, and are also present in the rumen (a part of stomach) of cattle.

The excreta of cattle, rich in methanogens and cellulosic material, is commonly called:

[Microbes-in-Human-Welfare] [class-xii ]

• Slurry
• Gobar
• Mycorrhiza
• Primary sludge
Correct Option: B  [ Gobar ]

Remark: The excreta (dung) of cattle, commonly called gobar, is rich in these bacteria.

The technology of biogas production was developed in India mainly due to the efforts of IARI and which other organization?

[Microbes-in-Human-Welfare] [class-xii ]

• KVIC
• WHO
• UNESCO
• NABARD
Correct Option: A  [ KVIC ]

Remark: The technology of biogas production was developed in India mainly due to the efforts of Indian Agricultural Research Institute (IARI) and Khadi and Village Industries Commission (KVIC).

Biocontrol refers to the use of:

[Microbes-in-Human-Welfare] [class-xii ]

• Chemical pesticides only
• Genetically modified crops
• Biological methods for controlling pests and diseases
• Physical barriers to pest entry
Correct Option: C  [ Biological methods for controlling pests and diseases ]

Remark: Biocontrol refers to the use of biological methods for controlling plant diseases and pests.

A key belief of the organic farmer regarding pest control is that increased landscape variety furthers health. This concept is referred to as:

[Microbes-in-Human-Welfare] [class-xii ]

• Monoculture farming
• Genetic modification
• Biodiversity
• Integrated Chemical Management
Correct Option: C  [ Biodiversity ]

Remark: A key belief of the organic farmer is that biodiversity furthers health. The more variety a landscape has, the more sustainable it is.

Which beetle, recognizable by its red and black markings, is useful to get rid of aphids?

[Microbes-in-Human-Welfare] [class-xii ]

• Dragonfly
• Praying Mantis
• Ladybird
• Weevil
Correct Option: C  [ Ladybird ]

Remark: The very familiar beetle with red and black markings – the Ladybird, is useful to get rid of aphids.