This set of Microbiology Multiple Choice Questions & Answers (MCQs) focuses on “Algae Biological and Economic Importance”.
1. Alginic acid is obtained from ______________
a) brown algae
b) red algae
c) yello-green algae
d) golden algae
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Explanation: Alginic acid and its salts are obtained from the walls of brown algae, where they may represent as much as 25 percent of the dry weight. Laminaria, Fucus are some of the species producing this compound.
2. Agar is obtained from the algal species of _______________
a) Chondrus
b) Gigartina
c) Gelidium
d) Laminaria
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Explanation: Species of Gelidium and Gracilaria belonging to red algae are extensively used for obtaining agar.
3. Carrageenan is used as a ______________
a) emulsifier
b) solidifying agent
c) binder
d) emulsifier and binder
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Explanation: Carrageenan has been used as a stabilizer or emulsifier in foods such as ice-cream and other milk products. It is also used as a binder in toothpaste or in pharmaceutical products, as well as an agent in ulcer therapy.
4. The famous Japanese dish sushi is made with the help of the red algae named ____________
a) Nemalion
b) Porphyra
c) Chondrus
d) Eucheuma
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Explanation: Porphyra is used as a food in Japan, where it is called “nori” and is usually processed into dried sheets. Nori is commonly toasted over a flame and sprinkled in soup or rice, or it is rolled around flavoured rice with fish or vegetables to make sushi.
5. Which among the following is a pathogenic algae for humans?
a) Prototheca
b) Chlorella
c) Cephaleuros
d) Acanthopeltis
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Explanation: Prototheca has been found to be a probable pathogen of humans. It has been found in systemic and subcutaneous infections, as well as in bursitis.
6. Algae are known as primary producers.
a) True
b) False
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Explanation: Algae form the base or beginning of most aquatic food chains because of their photosynthetic activities and are therefore called primary producers of organic matter.
7. Agar and carrageenan are polymers of _________________
a) glucose
b) phosphoric acid
c) starch
d) galactose
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Explanation: Agar and carrageenan are polymers of galactose, or galactose-containing compounds, with sulfated groups. Agar and carrageenan are both called sulfated galactans.
8. Which of the following species are important for cervical dilation?
a) Laminaria japonica
b) Gracilaria
c) Chondrus
d) Gonyaulax catenella
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Explanation: The stipe of the brown alga Laminaria japonica may be used by the physicians for cervical dilation and/or softening of the cervix (for example, in performing an abortion or placing a radium implant).
9. Which of the following algae continues to be a significant food in China?
a) brown algae
b) green algae
c) red algae
d) yellow algae
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Explanation: Red algae continue to be significant food in China. Such algae have been a food staple and delicacy for the Chinese for thousands of years.
10. Which of the following species produces neurotoxin which causes the death of aquatic animals?
a) Chlorella
b) Gonyaulax
c) Prototheca
d) Cephaleuros
View Answer
Explanation: It is known that certain dinoflagellates belonging to the genera Gymnodinium and Gonyaulax cause death of aquatic animals by producing a high molecular weight neurotoxin.
Sanfoundry Global Education & Learning Series – Microbiology.
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