This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Microbial Heterotrophs and Invertebrates”.
1. The eukaryotic groups of microalgae have plastids that resided into their cellular structure due to _____________________
a) endosymbiosis
b) conjugation
c) transformation
d) transfection
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Explanation: The eukaryotic algal groups have plastids that are entities derived from cyanobacteria (blue-green algae). Due to endosymbiotic events in which a cyanobacterium was engulfed by a larger eukaryotic microorganism led to the possession of plastid.
2. No secondary endosymbiosis event has been observed in the Glaucophyta lineage.
a) True
b) False
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Explanation: There are three main eukaryotic algal lineages that arose out of primary endosymbiosis events from prokaryotic cyanobacteria. The lineages are Glaucophyta, Rhodophyta and Chlorophyta; Glaucophyta is the most primitive and has not undergone secondary endosymbiosis like the other two phyla.
3. Euglenophyta is derived from which algal lineage?
a) Cyanophyta
b) Chlorophyta
c) Rhodophyta
d) Chlorarachniophyta
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Explanation: Euglenophyta is derived from the primary plastid algal lineage of Chlorophyta through secondary endosymbiosis event. The algal plastid of Euglenophyta is bounded by three membranes.
4. Phycobilisomes are ______________________
a) present only in Chlorophyta
b) water-soluble pigments
c) fat-soluble pigments
d) chlorophyll complex
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Explanation: Phycobilisomes are light-harvesting water soluble protein complexes that are larger in size than the chlorophyll pigments. Phycobilisomes are present as attachments on the thylakoid membrane.
5. In which of the following, the phycobiliproteins are distributed in the intrathylakoid membrane?
a) Cryptophyta
b) Dinophyta
c) Cyanophyta
d) Glaucophyta
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Explanation: Crytophyta was the first group in which secondary plastids were recognized. In their intra-thylakoid membrane region, the chlorophyll a and phycobiliproteins are distributed. The members of this group, known as cryptomonds also possess chlorophyll c.
6. Loss of nucleomorph from _____________________ led to evolution of Heterokonta lineage.
a) Apicomplexans
b) Dinoflagellates
c) Cryptophyta
d) Euglenophyta
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Explanation: Loss of nucleomorph from Chlorarachniophyta and Cryptophyta lineages led to the evolution of Heterokonta, Haptophyta and other lineages through second endosymbiosis events.
7. Which of the following is not a eukaryotic algal division?
a) Dinophyta
b) Rhodophyta
c) Glaucophyta
d) Prochlorophyta
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Explanation: In the taxonomic division of algae there are two prokaryotic members and nine eukaryotic members. Cyanophyta and Prochlorophyta belong to the former, and Dinophyta, Rhodophyta and Glaucophyta belong to the latter.
8. Which is not true in the context of Cyanobacteria?
a) Cyanobacteria are motile
b) Cyanobacteria have blue pigmentation
c) Cyanobacteria are gram-negative
d) Cyanobacteria are non-pathogenic
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Explanation: Cyanobacteria are gram-negative eubacteria that are non-motile. They are widely distributed and are the ancient most lineages of algae. They are plankton, benthic, symbiotic depending upon the habitat.
9. Cyanobacteria have __________________
a) stacked thylakoids
b) packaged DNA
c) 3-layered wall
d) 4-layered wall
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Explanation: Cyanobacteria have 4-layered wall and their thylakoids are not stacked. Rather the phycobilisomes-attached thylakoid membranes are singled and equidistant similar to Glaucophyta and Rhodophyta.
10. Heterocysts do not have _____________________
a) Photosystem I
b) Anoxic environment
c) Photosystem II
d) Glycolipid cell wall
View Answer
Explanation: Heterocysts are vegetative cells of cyanobacteria, characterized by absence of photosystem¬-II, a glycolipid cell wall and anoxic environment. The major role of heterocysts is providing a suitable environment for nitrogenase activity.
11. Akinetes only occur in cyanobacteria that for heterocysts.
a) True
b) False
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Explanation: Akinetes are larger in size than the vegetative cells due to granulation of highly concentrated glycogen and cyanophycin. Occurring only in cyanobacteria that have heterocysts, the akinetes are comparable to endospores in gram-positive bacteria.
12. Which group of characteristics is found in Trichodesmium?
a) Filamentous, heterocysts absent
b) Non-filamentous, heterocysts absent
c) Filamentous, heterocysts present
d) Non-filamentous, heterocysts present
View Answer
Explanation: Trichodesmium are tha major bloom-forming cyanobacteria that are filamentous and fix one quarter of total nitrogen in the oceans of the world. Trichodesmium do not have heterocysts and fix nitrogen under light and aerobic conditions.
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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