This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Marine Toxins”.
1. Which of the following is the most severe form of food poisoning caused by the ingestion of seafood?
a) Paralytic shellfish poisoning
b) Amnesic shellfish poisoning
c) Ciguatera
d) Diarrheic shellfish poisoning
View Answer
Explanation: Paralytic shellfish poisoning (PSP) is an acute and often fatal form of food poisoning caused by the ingestion of seafood. The toxins responsible for PSP are produced mainly by marine plankton Gonyaulax catenella and few other dinoflagellates.
2. The tetrodotoxin of the marine origin has been instrumental in the study of _____________________
a) iron fertilization
b) potassium channels
c) sodium channels
d) covalent linkages
View Answer
Explanation: Various toxins produced by inhabitants of the marine environment have been instrumental in the study of biological and pharmacological phenomena. Tetrodotoxin has been used in the study of sodium channels and nerve impulses.
3. The toxin responsible for paralytic shellfish poisoning (PSP) is saxitoxin.
a) True
b) False
View Answer
Explanation: Saxitoxin and its congeners such as neosaxitoxin are responsible for the PSP. The saxitoxin was first isolated from Alaskan butter clam, California mussel and the marine microalgae Gonyaulax catenella.
4. Which is the site of toxicity in filter-feeding shellfish?
a) Eye stock
b) Salivary glands
c) Digestive tract
d) Hepatopancreas
View Answer
Explanation: Hepatopancreas is the major site of toxicity in the shellfish. The toxins that are transferred from microalgae to shellfish as the former filter-feed on the latter accumulate and are retained for infinitely long time in the hepatopancreas.
5. In the assay developed by Johnson et al, Saxitoxin was coupled to BSA using _________________
a) formaldehyde
b) formamide
c) sodium chloride
d) sodium hypochlorite
View Answer
Explanation: In the immunoassay developed for the detection of Saxitoxin, it was coupled to bovine serum albumin (BSA) by formaldehyde treatment and antibodies prepared from rabbit antiserum.
6. Shewanella alga is the source of which marine toxin?
a) Tetrodotoxin
b) Okadaic acid
c) Neosaxitoxin
d) Brevetoxin
View Answer
Explanation: Shewanella alga produces tetrodotoxin that has a unique chemical structure that has a specific action of blocking sodium channels of excitable membbranes. Tetrodotoxin is a colorless crystalline compound insoluble in all organic solvents and soluble only in acidic medium.
7. Tetrodotoxin and saxitoxin do not have any effect on potassium ion channels.
a) True
b) False
View Answer
Explanation: Tetrodotoxin and saxitoxin are the most widely studied toxins from the marine origin. Although both are structurally dissimilar, both selectively block the transient Na+ current in the skeletal muscle and nerve tissues of animals, without having any effect on K+ channels.
8. Tetrodotoxin is used as a ____________________
a) muscle relaxant
b) rat killer
c) pesticide
d) bleaching agent
View Answer
Explanation: Tetrodotoxin acts at the entry point of sodium-ion channels and blocks the influx of sodium ions in the neuronal and skeletal muscle cells. It is hence commercially available and in small doses, used as a muscle relaxant.
9. Neurotoxic shellfish poisoning (NSP) is associated with _____________________
a) sea grass
b) sea cucumber
c) sea urchin
d) red tide
View Answer
Explanation: Neurotoxic shellfish poisoning is associated with the red tide, both of which are caused by the dinoflagellate Gymnodinium breve that forms blooms along the Florida coast. The red tide leads to mass mortality of fish and hence intoxication to those who consume it.
10. Ciguatera (seafood poisoning) is caused by the ingestion of ______________________
a) coral reef fish
b) krill
c) baleen fish
d) sea cucumber
View Answer
Explanation: Ciguatera is a form of seafood poisoning caused by ingestion of toxic coral reef fish that contain the toxins ciguatoxin and maitotoxin. These toxins are produced by the epiphytic dinoflagellate Gambierdiscus toxicus.
11. Gambieric acids are ____________ agents.
a) anti-fungal
b) anti-bacterial
c) thrombogenic
d) chelating
View Answer
Explanation: Gambreic acids is a family of polyether compounds of marine origin that act as antifungal agents. They have shown antifungal activity greater than that of amphotericin B against Apergillus niger.
12. Dinoflagellates in the genus Dinophysis cause which of the following?
a) Amnesic shellfish poisoning
b) Diarrheic shellfish poisoning
c) Paralysis
d) Anemia
View Answer
Explanation: Diarrheic shellfish poisoning is caused by the toxins from dinoflagellates in the genus Dinophysis. Even at cell densities as low as 200 cells per liter, the dinoflagellates cause the poisoning of shellfish.
13. Okadaic acid was first isolated from ___________________
a) marine sponge
b) cyanobacteria
c) sea urchin
d) sea horse
View Answer
Explanation: Okadaic acid is an inhibitor of protein phosphatase first isolated from the sponge Halichondria okadai, a black sponge commonly found along the Pacific Coast of Japan.
14. Which of the following has similar chromatographic properties as that of okadaic acid?
a) Dinophysistoxins
b) Brevetoxins
c) Saxitoxin
d) Tetrodotoxin
View Answer
Explanation: Dinophysis toxins such as the Dinophysistoxin1 (DTX1) were isolated from the digestive glands of mussels and were found with similar chromatographic properties as the okadaic acid.
15. Goniodomin-A is an antifungal _________________
a) ketone
b) lipid
c) polyketone
d) polyether
View Answer
Explanation: Goniodomin-A is an antifungal polyether first isolated from the dinoflagellate Goniodoma pseudogonyaulax in the rock pool at Jogashima, Kanagawa, Japan. Its structure resembles that of pectenotoxin.
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.
