Flow of energy in our ecosystem takes place :
In ecosystem, flow of energy takes place in only one direction. The flow of energy takes place from producers to final consumers. Energy present in one trophic levels nevers return back to producer.
Which of the following is CORRECT?
Net primary productivity (NPP) is equal to Gross primary productivity (GPP) minus Respiration loss (R). NPP is the available biomass for the consumption of heterotrophs in the ecosystem.
Producers in the aquatic ecosystem are :
Phytoplanktons are small floating photosynthetic unicellular plant. In the aquatic ecosystem phytoplankton are producers that fix solar energy by the process of photosynthesis.
Which of the following can be categorised as a photoautotroph ?
Photoautotrophs are organism that perform photosynthesis in presence of sunlight. Euglena contains chlorophyll and fixes the solar energy so, it acts as photoautotrophs.
Term ecosystem was introduced by :
The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley. Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment.
Which of the following ecological pyramid is always erect and upright?
Pyramid of energy is always erect and upright because the amount of energy get reduce at each trophic level from prouder to consumers.
Which of the following is NOT an ecological parameter?
Ecological parameter includes, biomass, energy and number of individual in the ecosystem. Stratification is not a part of ecological parameter.
Amount of biomass produced per unit area by green plants is called?
Primary productivity is the amount of biomass produced per unit area by green plants in an ecosystem. Producers fix the solar energy by the process of photosynthesis.
Organism/s living as both producer as well as consumer is/are:
Nepenthes (pitcher plant) and Drocera are insectivores plants to compensate their protein requirement. They have green leaves that perform photosynthesis process. So, they act as both producer as well as consumer.
Functional and dynamic unit of nature where living and non-living components interact with each-other is:
Ecosystem is the functional and dynamic unit of nature where living and non-living components interact with each other for flow of energy and biomass from producer to consumers.
Correct sequence for decomposition process is:
The correct option is Option A,C.
Decomposition is the process of breaking of complex organic matter into simpler inorganic matter. There are five steps of decomposition. These are fragmentation, leaching, catabolism, humification and mineralization. Fragmentation is the process of breaking of detritus into small pieces by detrivores such as earthworm.
Leaching is the process of releasing nutrients in the water and seeping into the soil.
Humification is the process of formation of dark colored substance humus on the soil. It undergoes microbial action at a slow rate. Mineralization is the process of degradation of the hummus to release inorganic nutrients.
Catabolism is the process of breaking down of complex molecules into the simpler molecules.
When the main pool is located in the soil and rocks, that nutrient cycle is called?
The nutrient cycle in which reservoir is located in earth crust is called sedimentary nutrient cycle. So, soil and rock based nutrient cycles are example of sedimentary nutrient cycle.
Which of the following pyramid/s is/are inverted?
The pyramid of biomass in an aquatic system is always inverted. Sharp decrease in biomass results into inverted pyramids.
Breakdown of detritus by microbial enzymes into simple forms is called?
Fragmentation is the process of breakdown of detritus in which a part of detritus is eaten by detritivores (such as earthworms) and comes out in highly pulverised state in their faeces.
So, the correct answer is 'Fragmentation'.
Conditions favouring decomposition are :
At a constant temperature, soil moisture content shows a parabolic affect on decomposition rates with a maximum rate at intermediate levels of moisture. High moisture content limits soil gas exchange leading to low oxygen concentrations and potentially anaerobic conditions. At low moisture content, the lack of water limits microbial metabolism; however, many microorganisms can remain active to much lower soil water potentials (at -3.0 MPa) than plants (at -1.5 MPa).
Available organic matter for herbivores is represented by:
In a food chain, energy stored at the producer level is called as primary productivity (PP). Net primary productivity (NPP) is the rate of storage of organic matter except which is utilized for the respiration by plants.
Speed of decomposition will be:
In detritus food chain, speed of decomposition will be fast if detritus is rich in simple sugar that can be easily decomposed into glucose by saprophytes that includes bacteria and fungi.
Correct decreasing order for rate of primary productivity on land will be :
Primary productivity is maximum in tropical rain forests due availability of sufficient food and water followed by temperate forests. Savannah grasslands have comparatively less productivity and arid regions have limited biotic component and water.
In which of the following places, succession will occur in short time?
Succession will occur in short time in heavily overgrazed pasture. If organic compound are already available in the place new organisms will develops faster as compare to bare land without organic matter.
Phosphorus will NOT make part of:
Phosphorus is not present in amino acids. Nucleic acids, ATP and Teeth contain phosphorus. Amino acids polymerases to form protein.
An ecological succession on bare land proceeds towards:
An ecological succession on bare land proceeds towards increasing wetness. Availability of water help in faster growth of organism including plants.
Humus will never be:
Humus is dark brown amorphous gummy substance formed by partial decomposition of plant and animal matter. Humus is quite resistant to microbial action. It is a reservoir of nutrients and is helpful in the maintenance of soil moisture as well as aeration.
Hence, None of these statements is correct about Humus.
Which one of the following is the most important service provided by ecosystems?
Ecosystem services includes all activities performed by nature to benefits of human beings. The most important ecological service includes soil formation. Soil is essential for growth of plants that provide food to all living forms.
The scientist who put price tag of US$ 33 trillion a year for nature’s life-support services was
Robert Constanza and his colleagues have recently put price tag of US$ 33 trillion a year for nature’s life support services for fundamental services.
Forest controls drought through
Forests helps in producing rainfall. More are the trees, the more water gets absorbed into clouds and the more it helps in rain falls. The roots of a tree make gaps in the soil so that when it rains the water can sink in before being absorbed by the soil. These spaces also allow air and water to reach the roots of the plants. If the forests disappear, there will be less rain resulting in dryer conditions, that eventually lead to drought. Once this happens, the damage is extensive making it difficult to plant more trees or plants later because the soil is so hard and dry. When trees removed using heavy machinery, the soil is pushed down and the gaps fill in. Because all plants and trees need that water and air to reach roots, the conditions become unfriendly for new growth.