This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Marine Algal Biotechnology – Set 6”.
1. Which method can be used to isolate epiphytes from micro-algae?
a) Sonication
b) Incubation
c) Chromatography
d) Distillation
View Answer
Explanation: To isolate epiphytes from marine micro-algae sonication can be used. The process leads to shaking off of the epiphytes and their subsequent accumulation in the medium following which they can be picked and rinsed.
2. Heterotrophic algae do not produce fluorescence.
a) True
b) False
View Answer
Explanation: Unlike autotrophic or photosynthetic algae, the heterotrophic algae do not produce fluorescence. This is the reason the latter are difficult to isolate from natural samples despite using enrichment cultures.
3. What can be used to efficiently remove fungal spores from phytoplankton culture?
a) Sodium bicarbonate
b) Malt extract
c) Sodium sulfate
d) Potassium sulfate
View Answer
Explanation: Being small in size fungal spores may also pass through the membrane filters as used in the initial steps of purification. Malt extracts or other enrichment methods can be used that leads to their germination after 1 – 2 days.
4. Agarose has higher purity than the agar.
a) True
b) False
View Answer
Explanation: Agarose have higher purity than the ordinary high-temperature gelling agars. Although the latter are usually used as in preparation of the agar plates for purification, these are also variously contaminated.
5. What must occur to efficiently ill the bacteria during micro-algal culturing?
a) Bacterial growth
b) pH drift
c) Change in medium color
d) Fungal contamination
View Answer
Explanation: Antibiotics are given to preclude the bacteria from contamination cultures of micro-algae. Efficient action of the antibiotics requires the bacteria in the culture to grow and divide so that bactericidal effect can take place.
6. Penicillin-G requires is mostly active against ____________
a) Gram-positive bacteria
b) Gram-negative bacteria
c) Micro-algae
d) Macro-algae
View Answer
Explanation: Penicillin-G is an antibiotic commonly used in micro-algal culturing to prevent the growth of gram-positive bacteria. Other antibiotics used include Kanamycin, Gentamycin, Cefotaxime and Ampicillin.
7. ____________ is a strong oxidizing agent used for phycological application.
a) Sulfonamide
b) Sodium bicarbonate
c) Tellurite
d) Titanium oxide
View Answer
Explanation: Tellurite is a strong oxidizing agent used in phycology, mostly gainst heterotrophic bacteria that might outgrow the desired algal species in culture. It is reduced to tellurium in bacterial species and stored as intracellular crystals leading to mortality.
8. In the algal culture medium malt extract favors the growth of ____________ while bovine serum favors _________
a) fungi, yeast
b) fungi, bacteria
c) yeast, fungi
d) yeast, bacteria
View Answer
Explanation: In algal culture medium addition of various organic and inorganic substrates favor the growth of various microbes. Malt extract favors the growth f filamentous fungi while bovine serum encourages yeast species to grow.
9. Which is a favored method of mass culturing of heterotrophic micro-algae?
a) Photobioreactor
b) Fermentor
c) Conventional bioreactor
d) Shake flasks
View Answer
Explanation: Depending upon the energy requirement, end purpose and species to be mass cultured the type of reactor can be chosen. In case of heterotrophic micro-algae the source of energy is organic carbon and they can be cultured in fermenters.
10. Which gene was used to transform Phaeodactylum tricornutum into a heterotroph?
a) Glut1
b) Glut2
c) Glut3
d) Glut4
View Answer
Explanation: Phaeodactylum tricornutum is an obligate phototroph despite having the ability to metabolize glucose intracellularly. Glut1 gene from human erythrocytes was used to transform it into a heterotroph.
11. Which configuration is better suited for photo-bioreactors?
a) Cylindrical
b) Rectangular
c) Intercalated discs
d) Thin piping
View Answer
Explanation: Rectangular configuration is better suited due to maximal availability of light. Light is refracted and reflected when it passes from medium of one index to another except when the angle of incidence is normal.
12. For high specific growth rate, the optical path should be ___________
a) matched with optical density
b) less
c) more
d) matched with light source
View Answer
Explanation: The optical path is very important parameter directly influence the growth rate of autotrophic algae. In case of closed bioreactors the gap between the walls should be less, while in case of open ponds the height of the water column should be low. Decreasing the optical path increases the growth rate.
13. Which is the most favorable light region for dense algal cultures?
a) Blue region
b) Green region
c) Yellow region
d) Red region
View Answer
Explanation: Three ranges of wavelengths are: Blue region 400-500 nm, 500-600 nm green region, and 600-700 nm is red region. The green region is the most poorly absorbed by chlorophyll and carotenoids and is hence able to penetrate longer distances making it most suited for light-limited dense algal cultures.
14. What is the optimal CO2 concentration for a photo-bioreactor being used for culturing micro-algae?
a) 1-2%
b) 2-5%
c) 0.2-5%
d) 10-15%
View Answer
Explanation: The concentration of CO2 in air is 0.033%, being less this might inhibit the growth phototrophic algae. The concentration for the air to be bubbled is made to 0.2-5%.
15. Which chemical can be used to sterilize sea water?
a) Sodium peroxide
b) Sodium persulfate
c) Sodium hypochlorite
d) Sodium benzoate
View Answer
Explanation: Sodium hypochlorite that contains 2.8%of free chlorine can be used to sterilize the seawater. After keeping overnight for sterilization the residual chlorine can be deactivated using sodium thiosulfate.
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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