biology : class12 Productivity Measurement : Primary Productivity, Secondary Productivity, Gross Productivity, Net Productivity : Productivity MCQ Questions and Answers
Practice important
Productivity Measurement
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. Which method commonly measures aquatic primary productivity by estimating oxygen released during photosynthesis?
A.
Light and dark bottle method
B.
Quadrat method
C.
Pitfall trap method
D.
Mark and recapture method
Correct Answer:
Light and dark bottle method
Explanation:
The light and dark bottle method estimates primary productivity from changes in dissolved oxygen caused by photosynthesis and respiration.
2. In the light and dark bottle method, the increase in oxygen in the light bottle mainly represents:
A.
Net primary productivity
B.
Secondary productivity
C.
Decomposer activity
D.
Consumer respiration only
Correct Answer:
Net primary productivity
Explanation:
The light bottle permits both photosynthesis and respiration, so the observed oxygen increase represents net primary productivity.
3. In the light and dark bottle method, the decrease in oxygen in the dark bottle is used to estimate:
A.
Respiration
B.
Gross photosynthesis
C.
Solar radiation
D.
Biomass production by consumers
Correct Answer:
Respiration
Explanation:
Photosynthesis does not occur in the dark bottle, so the decrease in dissolved oxygen is due mainly to respiration.
4. Which substance is commonly measured to estimate primary productivity in a water body?
A.
Dissolved oxygen
B.
Urea only
C.
Sodium chloride only
D.
Sand particles
Correct Answer:
Dissolved oxygen
Explanation:
Changes in dissolved oxygen provide a measure of oxygen production during photosynthesis and are used to estimate primary productivity.
5. Primary productivity can be expressed as the amount of biomass produced per unit:
A.
Area and time
B.
Temperature only
C.
Water depth only
D.
Number of species only
Correct Answer:
Area and time
Explanation:
Productivity is a rate, so primary productivity is commonly expressed as biomass or energy produced per unit area per unit time.
6. Which measurement is most directly used to estimate plant biomass production in a terrestrial ecosystem?
A.
Increase in dry weight
B.
Decrease in air pressure
C.
Increase in soil color
D.
Number of clouds
Correct Answer:
Increase in dry weight
Explanation:
The increase in dry biomass over a known area and time can be used to estimate terrestrial primary productivity.
7. Gross primary productivity is measured by considering:
A.
Total photosynthetic production before respiratory loss
B.
Only the biomass eaten by herbivores
C.
Only the biomass lost through decomposition
D.
The number of consumers in an ecosystem
Correct Answer:
Total photosynthetic production before respiratory loss
Explanation:
Gross primary productivity is the total rate of photosynthetic production, including the portion later used in respiration.
8. Net primary productivity can be calculated by subtracting respiration from:
A.
Gross primary productivity
B.
Secondary productivity
C.
Consumer biomass
D.
Decomposer biomass
Correct Answer:
Gross primary productivity
Explanation:
Net primary productivity is calculated using the relationship NPP = GPP − respiration.
9. Secondary productivity is measured as the rate of production of new biomass by:
A.
Consumers
B.
Sunlight
C.
Mineral particles
D.
Atmospheric oxygen
Correct Answer:
Consumers
Explanation:
Secondary productivity refers to the formation of new organic matter by consumers and can be measured as an increase in their biomass.
10. If gross primary productivity is 100 units and plant respiration is 30 units, what is the net primary productivity?
A.
70 units
B.
130 units
C.
30 units
D.
100 units
Correct Answer:
70 units
Explanation:
Net primary productivity equals gross primary productivity minus respiration: 100 − 30 = 70 units.
Short Questions and Answers
Practice short questions and answers related to
Productivity Measurement
.
Short questions are currently unavailable for this page.