This set of Marine Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Phytoplankton – Set 3”.
1. Change in shape is an adaptation for ______________________
a) reducing sinking
b) increasing sinking
c) maintaining pH
d) regulating light intensity
View Answer
Explanation: Phytoplankton must remain at adequate depth in the waters to ensure adequate light being captured by their cells. They are denser than the seawater and tend to sink down, to regulate the time of sinking the phytoplankton exhibit various shapes.
2. Which is not an adaptation of phytoplanktonic species to reduce the sinking rate?
a) Spiky structures
b) Color intensity changes
c) Surface area-to-volume variations
d) Diverse cell shapes
View Answer
Explanation: Since phytoplanktons are denser than sea water, it is essential for them to reduce the sinking rates. Color intensity variations in the phytoplankton depend on the photosynthetically active radiation (PAR) that they absorb and are not an adaptation to reduce the rate of sinking.
3. Which is a strategy of phtoplanktons to harvest more light?
a) Inactivating chloroplasts
b) Moving chloroplasts to cell edges
c) Aggregating chloroplasts
d) Producing low amounts of accessory pigments
View Answer
Explanation: Phytoplankton advertently move the chloroplasts to cell edges in order to harvest more light. This is one of the adaption of these organisms that are usually developed under conditions of environment stress.
4. Standing crop is the amount of ______________
a) total pelagic phytoplankton
b) the amount of plant material alive
c) total number of benthic plants
d) amount of organic carbon in the sea
View Answer
Explanation: There are two autotrophic primary producers belonging to the marine environment namely the pelagic phytoplankton and the benthic plants such as seaweeds. Standing crop of the benthic plants seems higher than the pelagic phytoplankton from the shore-based perspective. Standing crop refers to the amount of plant material that is alive at any given time.
5. Standing crops are governed by a balance between _______________________
a) crop increase and crop decrease
b) cell division and cell growth
c) sinking and grazing
d) cell division and sinking
View Answer
Explanation: Standing crops are governed by a balance between the crop increase and the crop decrease. In case of primary producers of the sea, the phytoplankton, the crop increase is the cell divison and growth and crop decrease is the cell sinking and grazing.
6. Diatoms and silicoflagellates thrive in low light intensities.
a) True
b) False
View Answer
Explanation: Diatoms and silicoflagellates thrive in low light intensities and colder waters. Dinoflagellates and coccolithophores on the other hand thrive in higher light intensities and warmer temperatures.
7. Compensation depth and critical depth refer to the same depth.
a) True
b) False
View Answer
Explanation: At the compensation depth, the net primary production is zero, however the energy for the respiration can be produced. At the compensation depth the rate of energy production equals the rate of energy being used by the phytoplankton respiration.
8. The photosynthetic apparatus of all primary producers is located in the _________________
a) stipe
b) chloroplasts
c) phycobilisomes
d) phycoerythrin
View Answer
Explanation: The photosynthetic apparatus of most of the primary producers is located in the chloroplasts. However, in the case of cyanobacteria the photosynthetic apparatus is located elsewhere.
9. Which is not a requirement for dark photosynthetic reactions to proceed?
a) Light of wavelength 600 nm
b) High-energy ATP
c) High-energy NADPH
d) Chloroplasts
View Answer
Explanation: Light dependent reactions require photosynthetically active radiation (PAR) of 400-700 nm to proceed. However for light-independent reactions, only high-energy ATP and NADPH are required for making carbohydrates, lipids and other organic material.
10. Which is a pigment found in red algae and cyanobacteria?
a) Fucoxanthin
b) Carotenoids
c) Fucocyanin
d) Phycoerythrin
View Answer
Explanation: Chlorophyll a absorbs light in the wavelength of 650-800 nm. For absorption of light at lower wavelengths, accessory pigments such as phycoerythrin and fucoxanthin are present in primary producers. Phycoerythrin is the pigment present in red algae and cyanobacteria that absorbs light of 570-650 nm.
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.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
