Marine Biotechnology Questions and Answers – Wastewater Management through Aquaculture

This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Wastewater Management through Aquaculture”.

1. Choose the correct option.

1. Pathogenic bacteria a. Salmonella
2. Probiotic bacteria b. Listeria
c. Bacillus
d. Carnobacterium

a) a-1, b-1, c-2, d-2
b) a-1, b-1, c-1, d-2
c) a-2, b-1, c-2, d-1
d) a-2, b-2, c-1, d-1
View Answer

Answer: a
Explanation: Microbes live in association with all life forms on the Earth and this goes for aquatic animals as well. Depending upon the feed ingested and water quality the population dynamics of pathogenic bacteria and probiotic bacteria changes.

2. Rice husk can be used as a biosorbent.
a) True
b) False
View Answer

Answer: a
Explanation: Adsorbents are used to catalyze the sorption of various heavy metals and facilitate their removal. Rice husk modified with acid, alkali, and various other chemicals has been reported to increase adsorption of heavy metals such as cadmium, lead etc.

3. Which is not achievable using bioremediation in aquaculture?
a) Reproduction alteration
b) Organic matter management
c) Ammonia management
d) Hydrogen sulfide management
View Answer

Answer: a
Explanation: Reproduction in aquatic animals is a natural phenomenon which involves interplay of many factors and is usually unachievable with bioremediation. Hydrogen sulfide, ammonia content and detritus (organic matter) can be managed well with biological remediation agents.

4. Select the incorrect option about Hydrogen sulfide.
a) H2S above 2 mg/L is tolerable
b) H2S behaves opposite of ammonia
c) H2S is the unionized toxic form
d) Air stripping by lowering pH removes H2S
View Answer

Answer: a
Explanation: Hydrogen sulfide (H2S) is a potent gas that arises as metabolic byproduct of sulfate reducing bacteria and other processes. It is highly toxic and over 2 mg/L leads to long-term hazards in fish.

5. Green sulfur bacteria are strict anaerobes.
a) True
b) False
View Answer

Answer: a
Explanation: Purple sulfur bacteria use hydrogen sulfide as source of hydrogen and carbon dioxide as a source of carbon in its metabolism. Characteristic of polluted waters, purple sulfur bacteria inhibits the growth of green sulfur bacteria.

6. Choose the correct option.

1. Acidic soil a. high fish production
2. Alkaline/ neutral soil b. low fish production

a) 1-a, 2-b
b) 1-b, 2-a
c) 1-a, 2-a
d) 1-b, 2-b
View Answer

Answer: b
Explanation: A pond with fertile soil results in higher fish yield compared to a pond having infertile soil. This is due to intrinsic buffering capacity and microbial activity housed within the soil. Alkaline or neutral soils are better suited for fish production having pH 6.5-7.5.

7. Choose the correct option.

1. Methane a. anaerobic conditions
2. Carbon dioxide b. organic matter decomposition
3. Calcitrant organic compounds c. decomposition in acidic conditions

a) 1-c, 2-b, 3-a
b) 1-b, 2-c, 3-a
c) 1-b, 2-a, 3-c
d) 1-a, 2-b, 3-c
View Answer

Answer: d
Explanation: Decomposition of organic matter (fish excreta, uneaten feed etc.) leads to formation of carbon dioxide and methane in anaerobic conditions. Decomposition of recalcitrant organic compounds occurs slowly under acidic conditions in a pond.

8. In wastewater-fed aquaculture systems, there is a higher incidence of _________________
a) low redox potential
b) high redox potential
c) low microbial activity
d) reduced organic matter
View Answer

Answer: a
Explanation: In wastewater fed aquaculture there is a higher incidence of low redox potential at soil water interface which leads to accumulation and diffusion of reduced organic substances into overlying water column.

9. Which is a negative set of conditions for a pond?
a) ↑phosphate solubility, ↑oxygen content, ↓reduction potential
b) ↑organic carbon input, ↓reduction potential, ↑oxygen content
c) ↑oxygen content, ↓phosphate solubility, ↓organic carbon input
d) ↓organic carbon input, ↑oxygen content, ↓phosphate solubility
View Answer

Answer: b
Explanation: Water quality parameters, soil-water interactions, and addition of organic carbon addition in a fish pond are intricately related. Higher organic carbon put leads to lower redox potential further leading to lowered oxygen content in the overlying water column.

10. Which of the following leads to characteristic earthy smell of polluted waters?
a) Actinomycetes
b) Coliforms
c) Algae
d) Phytoplankton
View Answer

Answer: a
Explanation: The characteristic composition of a wastewater depends on the source of the wastewater. Usually water originating from industrial sources has the highest concentration of recalcitrant compounds. Actinomycetes is a dominant bacteria present in soil and detritus mixed wastewater that imparts an earthy smell to it.

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.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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