This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Soil Microbiology”.
1. Which is not a biotic component of pond ecosystem?
a) Phytoplankton
b) Autotrophic bacteria
c) Saprophytes
d) Nutrients
View Answer
Explanation: Micro-and macro-consumers along with saprophytes as well as autotrophic bacteria form the biotic components of a pond ecosystem. The abiotic components are water, soil, nutrients, local climate.
2. Soil can act either as a carbon sink or source.
a) True
b) False
View Answer
Explanation: Depending upon the physical, chemical, and biological factors soil can act as a carbon source or sink. Carbon source is one that leads to elevated levels of carbon footprint in the environment.
3. Choose the correct option.
| i. Silver carp | a. Herbivorous fish |
| ii. Grass carp | b. Benthic-oriented |
| iii. Common carp | |
| iv. Tilapia | |
| v. Black carp |
a) i-a, ii-b, iii-a, iv-b, v-a
b) i-b, ii-a, iii-b, iv-a, v-b
c) i-a, ii-a, iii-b, iv-b, v-b
d) i-b, ii-b, iii-a, iv-a, v-a
View Answer
Explanation: Silver carp and grass carp are herbivorous fish, also known as low-carbon footprint fish. Common carp, black carp, and tilapia are benthic oriented fish the feed on benthic invertebrates, decayed vegetation, and detritus.
4. Which process can introduces particulates into a pond?
a) Erosion
b) Electrochemical bonding
c) Cementing
d) Aggregation
View Answer
Explanation: Erosional processes such as alluvial, fluvial, or that resulting from bioperturbation are mainly responsible for introduction of particulates in pond. The particulates can then form electrochemical bonding amongst them.
5. Choose the correct option.
| a. Sandy soil | i. high adsorption |
| b. Clay bottom soil | ii. heavy leaching |
a) a-I, b-i
b) a-ii, b-ii
c) a-ii, b-i
d) a-i, b-ii
View Answer
Explanation: Sandy soil as well as high clay bottom soil is not suitable for aquaculture pond. Sandy soils lead to heavy leaching in the water column above while high clay bottom soil leads to high adsorption and retention of gases and nutrients.
6. Nutrient content is higher in older ponds.
a) True
b) False
View Answer
Explanation: The organic load increases over time in aquaculture ponds therefore older ponds have a higher nutrient content than newly constructed ones. Depending upon the trophic state bottom soils can act as nutrient source or sink.
7. Pond having which of the following as bottom layer will account for least water loss?
a) Sandy soil
b) Loamy soil
c) High clay containing
d) High organic matter containing
View Answer
Explanation: A pond constructed from clay or clay loam as the bottom constituent loses least amount of water because seepage as in case of sandy soil bottom ponds is prevented. In wastewater-fed ponds vertical seepage does not occur.
8. ________________ refers to organic matter, compost and complexes made of organics.
a) Peat
b) Silt
c) Clay
d) Humus
View Answer
Explanation: Humus refers to the organic matter formed from a variety of organic compounds, having very high adsorption capacity. Humus is colloidal in nature and its presence in aquaculture ponds aids in better retaining of water.
9. Humic acid can act as a weak acid and a weak base.
a) True
b) False
View Answer
Explanation: Humic acid has high base change capacity and can act as a weak acid as well as weak base. It exerts beneficial effects on the growth of microalgae and other nutrient cycling bacteria in carbon-limiting systems.
10. Choose the correct option.
| i. Fibric soil or peat soil material | a. highly decomposed organic matter |
| ii. Muck or sapric soil material | b. plant tissue excluding roots |
| iii. Hemic soil material | c. contain plant fibers |
a) i-a, ii-b, iii-c
b) i-c, ii-b, iiii-a
c) i-b, ii-a, iii-c
d) i-b, ii-c, iii-a
View Answer
Explanation: Depending upon the composition, soil materials are broadly classified into fibric or peat soil materials, muck or sapric soil materials, and hemic soil materials. Wastewater-fed ponds mostly consist of muck or sapric soil materials having highly decomposed organic material.
11. Oxic bottom layers in ponds can control ____________________, which is desirable.
a) excessive phosphate
b) turbidity
c) plant growth
d) feed requirement
View Answer
Explanation: Oxic bottom layers in pond control excess phosphate levels in pond thereby keeping a check on the algal growth. Due to unchecked microbial degradation of organic matter oxic layer is disturbed.
12. Loss of oxic surface layer in pond bottom releases _________________
a) soluble ferrous phosphate
b) soluble sodium sulphide
c) insoluble ferric phosphate
d) insoluble sodium sulphide
View Answer
Explanation: Loss of oxic surface layer at the pond bottom mainly due to excessive microbial activity leads to release of insoluble ferric phosphate to which is converted to insoluble ferrous sulphate in the water column.
13. Redox potential decreases with increasing soil depth.
a) True
b) False
View Answer
Explanation: Redox potential is a physical property of the soil, with increase in depth the redox potential decreases. High rate of organic matter decomposition leads to lowered redox potential at the soil-water interface.
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]
