12th Grade > Biology
MICROBES IN HUMAN WELFARE MCQs
Total Questions : 51
| Page 5 of 6 pages
Answer: Option D. -> Lignin
:
D
Anaerobic digestionis a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage wastes to produce biogas or fuels. Microbes can degrade cellulose, hemicellulose and lipids easily beacause of their chemical structures which can be degarded by a class enzymes produced by these microbes but, complex polymers like lignin cannot be broken anaerobically. Enzymes involved in breakdown of lignin are secreted by a class of fungi and bacteria which are mostly aerobic in nature. Hence, lignin cannot be degraded during the process of bio gas production.
:
D
Anaerobic digestionis a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage wastes to produce biogas or fuels. Microbes can degrade cellulose, hemicellulose and lipids easily beacause of their chemical structures which can be degarded by a class enzymes produced by these microbes but, complex polymers like lignin cannot be broken anaerobically. Enzymes involved in breakdown of lignin are secreted by a class of fungi and bacteria which are mostly aerobic in nature. Hence, lignin cannot be degraded during the process of bio gas production.
Answer: Option D. -> All the above
:
D
Biofertilisers are the organisms that enrich the nutrient quality of the soil. The main sources of biofertlisers are bacteria, cyanobacteria and mycorrhiza.
1. Nitrogen fixing bacteria -These are the microorganisms present in the soil including Clostridium, Azotobacter etc. or in plant roots, for example Rhizobium. These bacteria are in a symbiotic association with the roots of legumesthat change nitrogen gases from the atmosphere into solid nitrogen compounds that plants can use in the soil.
2. Nitrogen fixing cyanobacteria - Cyanobacteria like Nostoc, anabaena, oscillatoria can fix atmospheric nitrogen into the root nodules of plants.
3.Mycorrhiza - a genus of fungi that is in a symbiotic association with plants is calledmycorrhiza. Mycorrhizasolubalises phosphorus from the soil and passes it to the plant.
Therefore, all of the above are examples of biofertilizers as they help increase soil fertility.
:
D
Biofertilisers are the organisms that enrich the nutrient quality of the soil. The main sources of biofertlisers are bacteria, cyanobacteria and mycorrhiza.
1. Nitrogen fixing bacteria -These are the microorganisms present in the soil including Clostridium, Azotobacter etc. or in plant roots, for example Rhizobium. These bacteria are in a symbiotic association with the roots of legumesthat change nitrogen gases from the atmosphere into solid nitrogen compounds that plants can use in the soil.
2. Nitrogen fixing cyanobacteria - Cyanobacteria like Nostoc, anabaena, oscillatoria can fix atmospheric nitrogen into the root nodules of plants.
3.Mycorrhiza - a genus of fungi that is in a symbiotic association with plants is calledmycorrhiza. Mycorrhizasolubalises phosphorus from the soil and passes it to the plant.
Therefore, all of the above are examples of biofertilizers as they help increase soil fertility.
Answer: Option B. -> Escherichia.coli and Bacillus thuringiensis
:
B
Bacillus thuringiensis is a very important bacterium which is used for its insecticidal properties. The gene of that confers insecticidal ability to the bacterium also known as the Cry geneis incorporated into the target host by the technique of genetic engineering.E coli has been extensively used for genetic engineering in animals. E.g The human variant of insulin is produced within the bacteria by the technique of recombinant DNA technology.By producing insulin this way, the cost to patients has dramatically dropped and the problem of immunological side effects have been disappeared. Therefore both Bt and E Coli are useful agents in genetic engineering.
:
B
Bacillus thuringiensis is a very important bacterium which is used for its insecticidal properties. The gene of that confers insecticidal ability to the bacterium also known as the Cry geneis incorporated into the target host by the technique of genetic engineering.E coli has been extensively used for genetic engineering in animals. E.g The human variant of insulin is produced within the bacteria by the technique of recombinant DNA technology.By producing insulin this way, the cost to patients has dramatically dropped and the problem of immunological side effects have been disappeared. Therefore both Bt and E Coli are useful agents in genetic engineering.
Answer: Option B. -> Negative effect
:
B
The collective term for the useful gases that are produced by bacteria is biogas. Biogas is produced by the action of anaerobic bacteria that can breakdown organic matter in waste into useful gases like methane, hydrogen etc. So supply of oxygen to the biogas plant will have a negative effect on the process of anaerobic decomposition of the wastes.
:
B
The collective term for the useful gases that are produced by bacteria is biogas. Biogas is produced by the action of anaerobic bacteria that can breakdown organic matter in waste into useful gases like methane, hydrogen etc. So supply of oxygen to the biogas plant will have a negative effect on the process of anaerobic decomposition of the wastes.
Answer: Option B. -> To digest all the nutrients using microbes
:
B
The liquid effluent from the primary sewage treatment step is rich in organic nutrients. This effluent cannot be allowed to be dumped into any water bodies as it will increase its BOD causing a lot of harm. Thus, microbes are used to act upon the effluent. These microbes digest all the nutrients and then the remaining effluent is passed on to the nearby water body safely.
:
B
The liquid effluent from the primary sewage treatment step is rich in organic nutrients. This effluent cannot be allowed to be dumped into any water bodies as it will increase its BOD causing a lot of harm. Thus, microbes are used to act upon the effluent. These microbes digest all the nutrients and then the remaining effluent is passed on to the nearby water body safely.
Answer: Option A. -> True
:
A
As strange as it sounds, it has been estimated that microbial cells outnumber the human cells by 10 folds. These microbes are mostly found in the human gut and other orifices. Most of them are very helpful to us and do not harm us.
:
A
As strange as it sounds, it has been estimated that microbial cells outnumber the human cells by 10 folds. These microbes are mostly found in the human gut and other orifices. Most of them are very helpful to us and do not harm us.
Answer: Option B. -> Alexander Fleming - penicillin
:
B
Alexander Fleming accidentally discovered the antibiotic penicillin in the year 1928.
:
B
Alexander Fleming accidentally discovered the antibiotic penicillin in the year 1928.
Question 48. Sewage treatment promises the production of biogas that could be used as a source of energy for various purpose. Indian villages have adopted the Biogas generation at a small scale using Cow dung as the raw material for production of Biogas.
How does sewage treatment help in biogas production?
How does sewage treatment help in biogas production?
Answer: Option C. -> The secondary sludge left behind after the flocs act on nutrients, produces biogas when acted upon by anaerobic bacteria.
:
C
The secondary sludge is left behind once the floc acts on the nutrients in the effluent. This sludge cannot be dumped into water bodies. Therefore it is channeled into a chamber where the anaerobic bacteria decompose them further and produce biogas. In this way sewage treatment plants can be used to produce biogas as well.
:
C
The secondary sludge is left behind once the floc acts on the nutrients in the effluent. This sludge cannot be dumped into water bodies. Therefore it is channeled into a chamber where the anaerobic bacteria decompose them further and produce biogas. In this way sewage treatment plants can be used to produce biogas as well.
Answer: Option B. -> False
:
B
While some microbes can produce chemicals that can help in lowering of the blood cholesterol levels, they do not possess any antibiotic activity. Statins are chemical substances obtained from certain fungi that can reduce the cholesterol levels in the blood of patients. Cyclosporine is also another bioactive molecule produced by fungi. This molecule has an immunosuppressive role and is used during organ transplant.
:
B
While some microbes can produce chemicals that can help in lowering of the blood cholesterol levels, they do not possess any antibiotic activity. Statins are chemical substances obtained from certain fungi that can reduce the cholesterol levels in the blood of patients. Cyclosporine is also another bioactive molecule produced by fungi. This molecule has an immunosuppressive role and is used during organ transplant.
Answer: Option B. -> Secondary sedimentation treatment
:
B
In the sewage treatment plant once the BOD levels of partially treated sewage effluent drops to a sufficiently low level, a second sedimentation process is carried out in a settling tank. In the secondary sedimentation the solid or bacterial floc is separated from the liquid. The separated solid floc is called a secondary or activated sludge. A small part of this activated sludge is used as an inoculum of decomposing bacteria and is pumped back into the secondary or biological treatment phase. After the activated sludge is separated from the effluent, the nutritionally and microbially poor liquid portion of the sewage is suitable for release into the environment without causing danger to aquatic lifeforms.
:
B
In the sewage treatment plant once the BOD levels of partially treated sewage effluent drops to a sufficiently low level, a second sedimentation process is carried out in a settling tank. In the secondary sedimentation the solid or bacterial floc is separated from the liquid. The separated solid floc is called a secondary or activated sludge. A small part of this activated sludge is used as an inoculum of decomposing bacteria and is pumped back into the secondary or biological treatment phase. After the activated sludge is separated from the effluent, the nutritionally and microbially poor liquid portion of the sewage is suitable for release into the environment without causing danger to aquatic lifeforms.
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