During which stage of the sewage treatment are the microbes used?
1. | Primary | 2. | Secondary |
3. | Tertiary | 4. | Quaternary |
Biogas is a mixture of:
1. | Methane, Carbon dioxide, and Hydrogen sulfide |
2. | Methane, Carbon dioxide, and Ammonia |
3. | Methane, Ammonia, and Hydrogen sulfide |
4. | Ammonia, Carbon dioxide, and Hydrogen sulfide |
A biological control being developed for use in the treatment of plant diseases is the fungus:
1. | Trichoderma | 2. | Pneumocystis |
3. | Claviceps | 4. | Epidermophyton |
‘Toddy’, a traditional drink of some parts in southern India, is made by fermenting sap from:
1. | Soyabean | 2. | Bamboo shoots |
3. | Palms | 4. | Sugarcane |
Consider the two statements:
I: | Indirectly, BOD is a measure of the organic matter present in the water. |
II: | The greater the BOD of wastewater, the more its polluting potential. |
1. Both I and II are correct
2. Only I is correct
3. Only II is correct
4. Both I and II are incorrect
What is true regarding the activated sludge generated during the secondary treatment of sewage water?
I: | It is made up of aerobic bacteria that sediment down |
II: | A large part of the activated sludge is pumped back into the aeration tank to serve as the inoculum. |
III: | A minor part of the sludge is pumped into large tanks called anaerobic sludge digesters. |
1. | Only I | 2. | Only II and III |
3. | Only I and III | 4. | I, II and III |
The major problem with the use of chemicals to control plant diseases and pests is:
1. High cost
2. Ineffectivity against most pathogens
3. Difficulty in production
4. Non-specific nature
What is incorrect regarding organic farming?
1. | It relies on controlling pests by natural predation rather than introduced chemicals. |
2. | A key belief of the organic farmer is that biodiversity furthers health. |
3. | Pests are totally eradicated. |
4. | Reduces dependence on toxic chemicals and pesticides. |
Match each item in Column I [Diazotroph] with the feature in Column II and select the correct answer from the codes given below:
|
Column I |
|
Column II |
A. |
Cyanobacteria |
a. |
Actinorhizal symbiont |
B. |
Frankia |
b. |
Do not form nodules |
C. |
Rhizobium |
c. |
Free-living nitrogen fixer |
D. |
Azotobacter |
d. |
Legume symbiont |
Codes
A | B | C | D | |
1. | a | b | c | d |
2. | b | a | c | d |
3. | a | b | d | c |
4. | b | a | d | c |
Arbuscular mycorrhizas are formed only by fungi in the division:
1. | Ascomycota | 2. | Glomeromycota |
3. | Basidiomycota | 4. | Microsporidia |