Environmental Biotechnology Questions on “Microalgal Species for Aquaculture”.
1. Micro-algae are an essential food source in rearing which of the following marine molluscs?
a) Zooplankton
b) Shrimp
c) Marine gastropods
d) Bacteria
Answer: d
Clarification: Bacteria is not a marine molluscs and hence, micro-algae is an essential food source in marine molluscs, whereas, Zooplankton, Shrimp and Marine gastropods depend on Micro-algae for an essential food source in the aquatic system.
2. The production of algae comprises about 30% of the operating costs in the bivalve hatchery.
a) True
b) False
Answer: a
Clarification: The microalgae serve as an essential food source for the aquatic bivalve molluscs. So, the production of algae comprises about 30% of the operating costs in the bivalve hatchery which is quite a lot to produce the algae live in a hatchery.
3. Which of the following process would increase the salt content in the soil?
a) Engineered biopiling
b) Soil salinization
c) Land farming
d) Bio-sparging
Answer: b
Clarification: Soil salinization is a process by which the salt content in the soil increases, to increase the speed and efficiency of Soil banking method when the space is limited, certain techniques like Engineered biopiling is often used, Bio-sparging is an In-situ technique.
4. Which of the following Sea water intrusions consists of a lot of Geo-chemical process and doesn’t include microalgae?
a) Inter-aquifer mixing
b) Anthropogenic contamination
c) Increasing dissolved oxygen
d) Mobilization of brines
Answer: c
Clarification: Sea water intrusions can be direct into aquifers or it is a combination of processes that consists of a lot of Geo-chemical processes like Inter-aquifer mixing, Anthropogenic contamination, water-rock interaction and Mobilization of brines, whereas, increasing the dissolved oxygen doesnot lead to soil salinity.
5. Which of the following are found in abundance in coastal saline water bodies?
a) Oxygen
b) NaCl
c) Nitrogen
d) Carbon monoxide
Answer: b
Clarification: Coastal saline soils contain salts which make them saline, where NaCl and Na2SO4 salts are present in abundance, whereas Oxygen, nitrogen and Carbon monoxide are gases and hence, air components and not salts.
6. Arrange these soluble cations (Na, Ca, K, Mg) in ascending order of abundance of soluble cations found in saline water bodies.
a) Na > Mg > Ca > K
b) Mg > Na > Ca > K
c) K > Mg > Ca > Na
d) Na > Mg > K > Ca
Answer: a
Clarification: Na > Mg > Ca > K is the correct order with respect to abundance of soluble cations found in saline costal soils, as Na is the major component of salt, so, it is found in higher abundance.
7. How does algae reaches the soil surface during dry season?
a) Capillary rise
b) Diffusion
c) Active transport
d) Passive transport
Answer: a
Clarification: Salt reaches the soil surface through Capillary rise during dry season making the soil saline and making the agricultural lands unproductive for crop growths, gases travel by diffusion, active transport requires energy whereas passive transport does not.
8. Which of the following is the process by which the saline water underlying freshwater rises upward into the freshwater zone?
a) Bio-remediation
b) Bio-degradation
c) Bio-magnification
d) Upconing
Answer: d
Clarification: Upconing is the process by which the saline water near the freshwater intrudes in and rises upward into the freshwater zone, Bio-magnification is the process by which toxic substances get deposited in the food chain, bio-degradation is the process that leads to degradation of compounds with the help of bacteria, Bio remediation is a process that uses microbial processes and converts toxic substances into less toxic or usable forms.
9. Which of the following is a method for managing the excess algae in marine ecosystem?
a) Drainage
b) Harmful algal blooms
c) Bio-remediation
d) Bio-degradation
Answer: a
Clarification: Drainage is a primary technique of controlling the soil salinity, whereas, Algal blooms produce toxins which leads to formation of dead zones in water, bio-degradation is the process that leads to degradation of compounds with the help of bacteria, Bio remediation is a process that uses microbial processes and converts toxic substances into less toxic or usable forms.
10. Which technique is not used to manage saline aquatic systems?
a) End-of-pipe
b) Subsurface drainage
c) Skimming well technology
d) Leaching
Answer: a
Clarification: End-of-pipe is a process which uses free water and air streams of various contaminates at the last stage of the process, whereas, subsurface drainage, skimming well technology, leaching techniques are used to manage excess salinity of soils.
11. The process of Leaching is basically the removal of soluble salts.
a) True
b) False
Answer: a
Clarification: Leaching is a type of hydro-technical method of reclamation for management and removal of the soluble salts beyond the root zone. This also affects the aquatic life nearby and leaching would definitely help in recovery.