12th Grade > Biology
ECOSYSTEM MCQs
Total Questions : 48
| Page 3 of 5 pages
Answer: Option D. -> All of the above
:
D
A number of processes are involved in decomposition. They are grouped into three categories, i.e., fragmentation of detritus, leaching and catabolism. Decomposition leads to the formation of two products, humus and inorganic nutrients (minerals). Processes involved in their formation are called humification and mineralisation respectively. Thus all these steps i.e fragmentation, leaching, catabolism, humification and mineralisation are important for the complete decomposition of detritus into simpler compounds and inorganic substances.
:
D
A number of processes are involved in decomposition. They are grouped into three categories, i.e., fragmentation of detritus, leaching and catabolism. Decomposition leads to the formation of two products, humus and inorganic nutrients (minerals). Processes involved in their formation are called humification and mineralisation respectively. Thus all these steps i.e fragmentation, leaching, catabolism, humification and mineralisation are important for the complete decomposition of detritus into simpler compounds and inorganic substances.
Answer: Option B. -> It is inverted in shape
:
B
Pyramid of energy is graphic representation of energyin varioustrophic levels. The pyramid of energy is always upright, because energy is lost from one trophic level to another, therefore energy decreases from the base to the apex of an energy pyramid.
:
B
Pyramid of energy is graphic representation of energyin varioustrophic levels. The pyramid of energy is always upright, because energy is lost from one trophic level to another, therefore energy decreases from the base to the apex of an energy pyramid.
Answer: Option B. -> Fish
:
B
In pond ecosystem, fishes occupy more than one trophic level. In the food chain of pond ecosystems phytoplantons are the producers upon which primary consumers like zooplanktons and fishes feed directly. However, the fishes may also act as a secondary consumer in other trophic levels by feeding on zooplanktons or other small fishes.
:
B
In pond ecosystem, fishes occupy more than one trophic level. In the food chain of pond ecosystems phytoplantons are the producers upon which primary consumers like zooplanktons and fishes feed directly. However, the fishes may also act as a secondary consumer in other trophic levels by feeding on zooplanktons or other small fishes.
Answer: Option B. -> soil and rocks
:
B
Phosphorus reservoirs are found basically in soil and sedimentary rocks, because unlike the other nutrients that cycle through the biosphere, phosphorus cannot be found in air in the gaseous state. This is because phosphorus is usually solid at normal temperatures and pressures, it is highly reactive and combines with other elements to form acids and salts. Therefore it mainly cycles through water, soil and sediments.
:
B
Phosphorus reservoirs are found basically in soil and sedimentary rocks, because unlike the other nutrients that cycle through the biosphere, phosphorus cannot be found in air in the gaseous state. This is because phosphorus is usually solid at normal temperatures and pressures, it is highly reactive and combines with other elements to form acids and salts. Therefore it mainly cycles through water, soil and sediments.
Answer: Option B. -> Aquarium
:
B
An artificial ecosystem meets all the criteria of a natural ecosystem but is made and controlled by humans.It is created to mimic a natural ecosystem. Aquarium is an artificial ecosystem as it has the biotic and abiotic components but it is created and maintained by man. Herbarium cannot be an ecosystem because it has no living components. Tissue culture is a scientific method of plant propagation and has no connection to ecosystem. Forest is a natural ecosystem which is sustainable by itself without human intervention.
:
B
An artificial ecosystem meets all the criteria of a natural ecosystem but is made and controlled by humans.It is created to mimic a natural ecosystem. Aquarium is an artificial ecosystem as it has the biotic and abiotic components but it is created and maintained by man. Herbarium cannot be an ecosystem because it has no living components. Tissue culture is a scientific method of plant propagation and has no connection to ecosystem. Forest is a natural ecosystem which is sustainable by itself without human intervention.
Answer: Option A. -> Tropical rain forest
:
A
The decomposition process is affected by many factors like soil structure, quality of detritus, pH, etc. Temperature and soil moisture are the most important climatic factors that regulate decomposition through their effecton the activities of soil microbes. Warm and moist environment favour decomposition whereas low temperatures and dry conditions inhibit decomposition resulting in the build-up of organic materials. Decomposers are very active in soils having a temperature of more than 25 °C, with good moisture and aeration. Similar conditions prevail in the soil of tropical regions like the tropical rain forests. Antarctic and alpine regions have low temperatures not favouring decomposition.
:
A
The decomposition process is affected by many factors like soil structure, quality of detritus, pH, etc. Temperature and soil moisture are the most important climatic factors that regulate decomposition through their effecton the activities of soil microbes. Warm and moist environment favour decomposition whereas low temperatures and dry conditions inhibit decomposition resulting in the build-up of organic materials. Decomposers are very active in soils having a temperature of more than 25 °C, with good moisture and aeration. Similar conditions prevail in the soil of tropical regions like the tropical rain forests. Antarctic and alpine regions have low temperatures not favouring decomposition.
Answer: Option C. -> stored in the body tissue
:
C
According to the 10% rule, only 10% of energy is transferred from one level to the next level of food chain, and in the remaining 90% some part is used up metabolically for survival and the rest is lost as body heat. This 10% that is transferred to the next trophic level is basically what is stored in the body tissue as food, and utilized as food by organisms in the higher trophic level.
:
C
According to the 10% rule, only 10% of energy is transferred from one level to the next level of food chain, and in the remaining 90% some part is used up metabolically for survival and the rest is lost as body heat. This 10% that is transferred to the next trophic level is basically what is stored in the body tissue as food, and utilized as food by organisms in the higher trophic level.
Answer: Option A. -> Both A and R are true and R explains A
:
A
Solar radiation forms a spectrum called the electromagnetic spectrum. In the spectrum, there are three relevant bands or ranges- UV, visible light and infrared. Of the total incident solar radiation or energy, only a fraction of it,which is light in the 400 to 700 nanometer wavelength rangeis capable of enabling photosynthesis.This proportion of radiation is known as photosynthetically active radiation or PAR.PAR also changes seasonally and varies depending on the latitude and time of day.
:
A
Solar radiation forms a spectrum called the electromagnetic spectrum. In the spectrum, there are three relevant bands or ranges- UV, visible light and infrared. Of the total incident solar radiation or energy, only a fraction of it,which is light in the 400 to 700 nanometer wavelength rangeis capable of enabling photosynthesis.This proportion of radiation is known as photosynthetically active radiation or PAR.PAR also changes seasonally and varies depending on the latitude and time of day.
Answer: Option A. -> Stratification
:
A
Stratification is the characteristic of a biological community.Depending upon the physical and physiological requirement of the diverse species in a biological community, the organisms are organised in a recognizable structure or pattern called stratification. For eg. a forest ecosystem can be stratified into the upper canopy, the middle understory and the lower ground levels. Natality (The ratio of number of births to the size of population), mortality (The number of deaths in a given area or period)and sex ratio (number of males per thousand females in the population of a community) are the charateristics of population in a community.
:
A
Stratification is the characteristic of a biological community.Depending upon the physical and physiological requirement of the diverse species in a biological community, the organisms are organised in a recognizable structure or pattern called stratification. For eg. a forest ecosystem can be stratified into the upper canopy, the middle understory and the lower ground levels. Natality (The ratio of number of births to the size of population), mortality (The number of deaths in a given area or period)and sex ratio (number of males per thousand females in the population of a community) are the charateristics of population in a community.
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