This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Bioactive Metabolites of Marine Fungi”.
1. Substances that are toxic to fish are called __________________
a) bacteriotoxins
b) isotoxins
c) piscitoxins
d) ichthyotoxins
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Explanation: The toxic molecular compounds of natural origin that are either produced by the fish or are toxic to fish are called ichthyotoxins. Pseudomonas piscida is an ichthyotoxic bacteriathat also exhibits antagonism to other microbes.
2. Which of the following is sourced from the marine fungus Cephalosporium acremonium?
a) Saxitoxin
b) Cephalosporin
c) Kainic acid
d) Alginic acid
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Explanation: Cephalosporium acremonium is a marine fungus that produces cephalosporin C, active against Gram-negative bacteria. Cephalosporin C is a penicillinase-sensitive antibiotic also termed antibiotic N.
3. Cephalosporin P is active against Gram-negative bacteria.
a) True
b) False
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Explanation: Cephalosporium acremonium is a fungus that synthesizes antibiotic secondary metabolites of clinical importance. The cephalosporin P synthesized by the fungus is active against Gram-posistive bacteria.
4. Which of the following antibiotic is insensitive to penicillinase?
a) Cephalosporin C
b) Cephalosporin P
c) Cephalosporin N
d) Cephalothin
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Explanation: Cephalothin is a semi-synthetic derivate of cephalosporin C (active against Gram-negative bacteria), having action similar to that of benzylpenincillin but unlike cephalosporin C, insensitive to penicillinase.
5. Which compound is marketed under the name PYRO-ACE?
a) Pyrrolnitrin
b) Digenin
c) Carrageenan
d) Prodigiosin
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Explanation: Pyrrolnitrin derived from Pseudomonas pyrrocinia is a chloropyrrole that possesses high antibiotic activity against dermatophytic fungi. It was marketed under the name PYRO-ACE in Japan.
6. Antibiotic of which color is furnished by Serratia marcescens?
a) Purple
b) Green
c) Red
d) White
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Explanation: A red-colored antibiotic named prodigiosin is furnished by the non-pathogenic bacterium Serratia marcescens. It has high antibiotic and antifungal activity but the therapeutic use is precluded by its toxicity.
7. The dinoflagellate Dinophysis is responsible for ______________________
a) coloration of surroundings
b) pH imbalance
c) antifungal activity
d) shellfish poisoning
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Explanation: The dinoflagellate Dinophysis secretes toxins that are responsible for shellfish poisoning. Many dinoflagellates and sponges secrete toxins related to the okadaic acid, a potent neurotoxin and phosphatase inhibitor.
8. Which of the following is caused by Lyngbya majuscula?
a) Shellfish poisoning
b) Red tide
c) Swimmer’s itch
d) Hypoxia
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Explanation: Lyngbya majuscula is filamentous and fine seaweed (algae) of brown color that is toxic in nature. It causes skin irritation and swimmer’s itch. Other toxins might as well contribute to the ailment.
9. Which of the following is an exogenic toxin of Anabaena flosaquae?
a) Anatoxin-a
b) Anatoxin-b
c) Anatoxin-c
d) Anatoxin-d
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Explanation: Anatoxin-a is an exogenic toxin produced by the blue-green algae Anabaena flosaquae and other cyanobacteria in freshwater systems. Anatoxins cause a prolonged inhibition of acetylcholinesterase.
10. Avrainvilleol is a ________________ metabolite of green algae.
a) brominated
b) chlorinated
c) iodized
d) carboxylated
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Explanation: Avrainvilleol is a brominated metabolite of green algae Avrainvilleal ongicaulis. This marine natural compound is toxic towards reef fishes, possesses antibacterial activity and induces feeding deterrence.
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.