This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Marine Algal Biotechnology – Set 7”.
1. Collection of algal mass by addition of polymers is called _____________________
a) agglutination
b) sterilization
c) flocculation
d) precipitation
View Answer
Explanation: Addition of polymers to collect the algal cells is called flocculation which results in collected of the cell mass into aggregate. It is a technique of harvesting and takes place after adequate growth has occurred.
2. Coagulation and flocculation refer to the same procedure used in harvesting.
a) True
b) False
View Answer
Explanation: Flocculation and coagulation are different techniques of harvesting of algal cells. Coagulation uses pH adjustment or electrolyte addition to aggregate the cells while flocculation uses polymers.
3. Which compound is produced by Dunaliella salina to reduce the external salt pressure?
a) Starch
b) Glycerol
c) Chlorophyll a
d) Chlorophyll b
View Answer
Explanation: Dunaliella salina is an extromophilic algae belonging to Chlorophyta (the green algal group) however it is pink in color. This algae thrives in environments thrice as saline as the seawater (1.5-3M NaCl). To reduce the salt pressure of external environment glycerol is produced by the organism.
4. Ponds with lower mixing show higher productivities.
a) True
b) False
View Answer
Explanation: Ponds with continuous mixing at high rates show better productivity. Turbulent flow i.e. mixing is essential for maximum production of various kinds of micro-algae in open ponds.
5. In the culture of Spirulina _______________ is added to maintain high alkalinity.
a) Carbon dioxide
b) Oxygen
c) Nitrogen
d) Carbon monoxide
View Answer
Explanation: Spirulina is a species of micro-algae that is widely consumed being considered as a super-food. It requires high alkalinity (pH 8 and above) which is often maintained by provision of carbon dioxide.
6. In freshwater and marine cultures, rotifers impair the growth of algae what can be done to curb this?
a) Adding antibiotics
b) Adding germanium oxide
c) Lowering the pH
d) Elevating the pH
View Answer
Explanation: Growth off rotifers in freshwater and marine micro-algal cultures can be checked by lowering the pH of the pond to a value between 2 to 3 and allowing to stand for 1-2 hours. The pH can then be readjusted to 7.5 using potassium hydroxide.
7. Which of the following is not a colorless alga?
a) Prototheca
b) Polytomella
c) Astasia
d) Spirulina
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Explanation: All others (given in the answer choices) are colorless algae devoid of pigments while Spirulina is a blue-green alga. The colorless algal cultures are kept in closed cupboards unlike their counterparts.
8. Culture medium with no/low nitrogen induces the formation of _____________________
a) heterocysts
b) aplanospores
c) zoospores
d) spores
View Answer
Explanation: While propagating cultures from maintenance cultures to active use cultures, the culture medium should be changed. Low level or complete absence of nitrogen will ensue the formation of heterocysts.
9. Which is a non-permeating cryoprotective agent?
a) HES
b) DMSO
c) Glycerol
d) Methanol
View Answer
Explanation: Cryoprotective agents (CPAs) are added prior to cryopreservation of micro-algal cultures. There are two kinds of CPAs namely permeating and non-permeating, the latter is rarely used in micro-algae, an example is hydroxyethyl starch (HES).
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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