This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Sustainable Marine Food Production Systems – Set 6”.
1. Low dissolved oxygen concentration can be achieved using low-head oxygenators.
a) True
b) False
View Answer
Explanation: Low head oxygenation (LHO) devices can provide low concentration of dissolved oxygen in recirculating aquaculture devices. These devices are operated by gravity, are larger in size thereby incurring high initial cost.
2. Anammox is _____________________
a) ammonia removal pathway
b) oxygenation device
c) bacterial consortium
d) dropping of pH
View Answer
Explanation: Anammox is an alternative biological ammonia removal pathway that takes place under anaerobic conditions. In this bacterial pathway nitrogen gas is removed by combining ammonia and nitrites.
3. Choose the correct option.
| 1. Ion exchange | a. brackish water |
| 2. Electrochemical oxidation | b. freshwater |
a) 1-a 2-a
b) 1-a 2-b
c) 1-b 2-b
d) 1-b 2-a
View Answer
Explanation: Chemical removal of ammonia can be done by ion exchange or electrochemical oxidation. Ion exchange involves use of adsorptive materials and is suited for freshwater culture species whereas chemical oxidation is suitable for brackish water culture application.
4. For anammox reaction to take place addition of organic carbon is required.
a) True
b) False
View Answer
Explanation: Annamox is of interest to recirculating aquaculture systems (RAS) because it does not require addition of organic carbon as in traditional nitrifying biofilters. Anammox results in complete autotrophic ammonia removal.
5. Which is not a sign of fine solids accumulation in RAS?
a) Decrease in pH
b) Increase in turbidity
c) Hampered visual inspection
d) Imbalance in photoperiod control
View Answer
Explanation: Over 90% of solids produced in aquaculture are fine solids less than 30 micrometers in size. Increase in accumulation of fine solids leads to increased turbidity and hampered visual inspection and photoperiod control.
6. Cartridge filtration is used for ___________________
a) nitrification
b) suspended solid removal
c) fine solids removal
d) sulfide bioremediation
View Answer
Explanation: Fine solids form the major part of solids in recirculating aquacultures. Techniques to remove fine solids include cartridge filtration, protein skimming, foam fractionation, floatation, and membrane filtration.
7. _______________ can be used to improve performance of micro-screen filters.
a) Ozonation
b) Foam fractionation
c) Floatation
d) Biofilter
View Answer
Explanation: Knowledge on ozonation exists since 1970s however its application in aquaculture is not widespread. Besides improving the performance of micro-screen filters, it aids in improving the water quality.
8. In aquaculture ozonation cannot cause ___________________
a) autotrophic growth
b) oxidative stress
c) histopathological damage
d) bromate production
View Answer
Explanation: Besides improving the performance of micro-screen filters, ozonation levels greater than threshold lead to production bromate and other ozone-produced oxidants. Other side effects include altered feeding behavior and histopathological damage to fish tissues.
9. Nitrate removal is conventionally done by __________________
a) filter sterilization
b) dilution
c) autoclaving
d) chemical oxidation
View Answer
Explanation: Nitrate removal is done by dilution i.e. addition of new water in the aquaculture systems. Nitrate is the end product of nitrification – a process undertaken by microbes in the culture system.
10. _________________ is used as carbon source by denitrifying bacteria in zero-water exchange systems.
a) Volatile fatty acids
b) Molasses
c) Ethanol
d) Methanol
View Answer
Explanation: Zero exchange recirculating aquaculture system employs anaerobic digestion of biosolids in the system in order to produce volatile fatty acids. VFAs are then used as carbon source by the denitrifying bacteria.
11. Choose the appropriate option.
| 1. K-strategists | a. mature microbial communities |
| 2. R-strategists | b. pathogens |
a) 1-a, 2-b
b) 1-a, 2-a
c) 1-b, 2-b
d) 1-b, 2-a
View Answer
Explanation: To insure sustainable marine food production systems, a thorough understanding of life support process from physical, chemical and biological processes is necessary. K-strategists must always outnumber and prevent the growth of R-strategists.
12. Humic substances are _________________
a) organic compounds
b) chemical substances
c) bacterial communities
d) pathogenic flocculation
View Answer
Explanation: Humic substances (HS) comprise a wide variety of high molecular weight pigmented polymers that are natural and organic in nature. HS are end products of degradation of complex organic wastes.
13. ______________ is not an effect of presence of humic substances in aquaculture.
a) Fungistatic
b) Brown coloration of soil
c) Increased fish infection
d) Protection against toxic metals
View Answer
Explanation: According to several reports humic substances have proven benefits in aquaculture systems. These include fish resistance to infection, protective effect against toxic metals, and decreased infection intensity.
Sanfoundry Global Education & Learning Series – Marine Biotechnology.
To practice all areas of Marine Biotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.
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