This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Bioactive Metabolites of Marine Bacteria”.
1. Which of the following marine bacteria is N2 fixer?
a) Pseudomonas piscida
b) Cyanobacteria
c) Archae
d) Denitrifiers
View Answer
Explanation: Cyanobacteria is a marine microbe reduce nitrogen to ammonium and are hence N2 fixers, also termed ‘diazotrophs’. Cyanobacteria, the other name of blue-green algae and play an important role in regulating the oceanic processes.
2. The microbes that fix CO2 to produce organic material are called ___________________
a) Diazotrophs
b) Grazers
c) Primary producers
d) Photoheterotrophs
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Explanation: Eukaryotes and Cyanobacteria are the primary producers that fix carbon dioxide to produce organic matter using light energy from the Sun. This group of microbes has the most important function in the pelagic food web.
3. Dissolved organic matter (DOM) oxidizing bacteria are ___________________
a) heterotrophic prokaryotes
b) nitrifiers
c) denitrifiers
d) photoheterotrophs
View Answer
Explanation: Heterotrophic prokaryotes (bacteria and archaea) are responsible for mineralizing and oxidizing the dissolved organic matter (DOM) to produce biomass and inorganic byproducts.
4. The Calvin–Benson–Bassham cycle is used by ________________________
a) cyanobacteria
b) invertebrates
c) phytplankton
d) mammals
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Explanation: Like the terrestrial plants, the phytoplanktons, responsible for the primary production (of organic matter) in the sea use the Calvin–Benson–Bassham cycle for fixing atmospheric carbon dioxide.
5. Fucoxanthin is a __________________
a) carotenoid
b) alkaloid
c) terpenoid
d) thylakoid
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Explanation: Fucoxanthin is a carotenoid, the light-absorbing pigment present in phytoplankton to aid in the process of photosynthesis. Phytoplankton use pigments other than the chlorophyll, for this purpose.
6. Cyanobacteria account for over 90% of primary production in oligotrophic oceans.
a) True
b) False
View Answer
Explanation: Cyanobacteria are primary producers that account for approximately 90% of the primary producers and phytoplankton biomass in nutrient-poor, oligotrophic nutrients.
7. Which of the following is a marine cyanobacterium?
a) Pseudomonas
b) Laurencia glandulifera
c) Synechococcus
d) Thiobacillus
View Answer
Explanation: Synechococcus and Prochlorococcus are members of the cyanobacteria that are large contributors to primary production and phytoplankton biomass. Cells in these groups are smaller than those of eukaryotic phytoplankton.
8. The blue color of cyanobacteria (blue-green algae) comes from _____________________
a) phycocyanin
b) fucoxanthin
c) xylem
d) phloem
View Answer
Explanation: Blue-green algae is the name previously used for the cyanobacteria. The green is due to the presence of chlorophyll a and the blue is due to the presence of the pigment phycocyanin.
9. In pure-cultures, marine Synechococcus (cyanobacteria) is _____________________
a) mold-like
b) highly toxic
c) blue-colored
d) red-colored
View Answer
Explanation: Marine Synechococcus is one of the main cyanobacteria found in the oceans. It possesses phycocyanin (blue-colored pigment) but in pure cultures it gives a blood-red color due to the presence of phycoerythrin.
10. ‘Picoplanktons’ are larger than cyanobacteria.
a) True
b) False
View Answer
Explanation: ‘Picoplanktons’ having the size of 2 m or less, are slightly larger than the cyanobacteria. Picoplantons form a group of microbes that are hard to identify due to lack of distinguishable characteristics.
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.
