54778.Pyramid of numbers is
Always upright
Always inverted
Either upright or inverted
Neither upright nor inverted
Explanation:
Pyramid of numbers in ecosystems can be inverted or upright. In terrestrial ecosystem pyramids of numbers is upright. In case of successive decrease in members of trophic level in case of insects taking food from a tree, the number pyramid will be inverted.. On the other hand, small number of herbivores feeding on large number of plants will give an upright number pyramid.
Pyramid of numbers in ecosystems can be inverted or upright. In terrestrial ecosystem pyramids of numbers is upright. In case of successive decrease in members of trophic level in case of insects taking food from a tree, the number pyramid will be inverted.. On the other hand, small number of herbivores feeding on large number of plants will give an upright number pyramid.
54779.Approximately how much of the solar energy that falls on the leaves of a plant is converted to chemical energy by photosynthesis?
Less than 1 %
2-10%
30%
50%A
Explanation:
The photosynthetic process captures 2-10% of the Photosynthetically Active Radcation (PAR).
The photosynthetic process captures 2-10% of the Photosynthetically Active Radcation (PAR).
54780. Among the following where do you think the process of decomposition would be the fastest?
Tropical rain forest
Antarctic
Dry arid region
Alpine region
Explanation:
The lowest strata/storey/forest floor of the tropical rain forest recieve little solar radiation and soil is rich in mineral and humusAs the high temperature and moisture (humidiiy) are favourable for high microbial activity of decomposers to decompose the fallen leaves and dead organic matter, process of decomposition is fastest in this type of biome
The lowest strata/storey/forest floor of the tropical rain forest recieve little solar radiation and soil is rich in mineral and humusAs the high temperature and moisture (humidiiy) are favourable for high microbial activity of decomposers to decompose the fallen leaves and dead organic matter, process of decomposition is fastest in this type of biome
54781.How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
1%
10%
40%
90%
Explanation:
According to the 10% law of energy flow in a food chain, only 10% of herbivore productivity is utilised for raising productivity of next tropic level (primary carnivores), while the rest 90% is eaten and used up, in process like respiration, maintenance of body heat and other activities.
According to the 10% law of energy flow in a food chain, only 10% of herbivore productivity is utilised for raising productivity of next tropic level (primary carnivores), while the rest 90% is eaten and used up, in process like respiration, maintenance of body heat and other activities.
54782.During the process of ecological succession the changes that take place in communities are
orderly and sequential
random
very quick
not influenced by the physical environment
Explanation:
The gradual and predictable changes in the species composition of a given area are termed as ecological succession. These changes are orderly and sequential. The other options as random or quick change are not the features of ecological succession. Also the ecological succession is influenced by physical environment thus all the other options are wrong.
The gradual and predictable changes in the species composition of a given area are termed as ecological succession. These changes are orderly and sequential. The other options as random or quick change are not the features of ecological succession. Also the ecological succession is influenced by physical environment thus all the other options are wrong.
54783.Climax community is in a state of
non-equilibrium
equilibrium
disorder
constant change
Explanation:
During ecological or biotic succession, climax community is stable, self perpetuating and is the final biotic community. It is developed at the end of succession and is in state of perfect hormony and equilibrium with physical environment. Climax community has maximum diversity and niche specialization.
During ecological or biotic succession, climax community is stable, self perpetuating and is the final biotic community. It is developed at the end of succession and is in state of perfect hormony and equilibrium with physical environment. Climax community has maximum diversity and niche specialization.
54784.Among the following bio-geo-chemical cycles which one does not have losses due to respiration?
Phosphorus
Nitrogen
Sulphur
All of these
Explanation:
Phosphorus, nitrogen and sulphur biogeochemical cycle does not have any losses due to the process of respiration, while cycles like carbon and oxygen are affected by the process of respiration.
Phosphorus, nitrogen and sulphur biogeochemical cycle does not have any losses due to the process of respiration, while cycles like carbon and oxygen are affected by the process of respiration.
54785.The sequence of communities of primary succession in water is
Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and trees.
Phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses and
trees
Free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and trees.
Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.
Explanation:
The sequences of communities of primary succession in hydrosphere is phytoplankton (pioneer stage) → rooted submerged hydrophytes → floating hydrophytes (floating stage)→reed swamp→ sedges →meadow and woodland (trees).
The sequences of communities of primary succession in hydrosphere is phytoplankton (pioneer stage) → rooted submerged hydrophytes → floating hydrophytes (floating stage)→reed swamp→ sedges →meadow and woodland (trees).
54786.The reservoir for the gaseous type of bio-geochemical cycle exists in
stratosphere
atmosphere
ionosphere
lithosphere
Explanation:
There are two stores of nutrients reserve pool and cycling pool. The reservoir for gaseous type of nutrient and biogeochemical cycle (nitrogen and carboncycle) exists in atmosphere while earth crust is the reservoir for sedimentry cycle. On the other hand, stratosphere ionosphere and lithosphere are the parts of atmosphere.
There are two stores of nutrients reserve pool and cycling pool. The reservoir for gaseous type of nutrient and biogeochemical cycle (nitrogen and carboncycle) exists in atmosphere while earth crust is the reservoir for sedimentry cycle. On the other hand, stratosphere ionosphere and lithosphere are the parts of atmosphere.
54787.If the carbon atoms fixed by producers already have passed through three species, the trophic level of the last species would be
scavenger
tertiary producer
tertiary consumer
secondary consumer
Explanation:
Primary consumerSecondary consumerTertiary consumerProducerIst Trophic levelIInd Trophic level IIIrd Trophic level Scavengers are the detrivores which feeds on the tissue of dead animals (e.g., vultures) and do not play role in carbon fixation. Producers fix the carbon dioxide which is passed through the different trophic level.
Primary consumerSecondary consumerTertiary consumerProducerIst Trophic levelIInd Trophic level IIIrd Trophic level Scavengers are the detrivores which feeds on the tissue of dead animals (e.g., vultures) and do not play role in carbon fixation. Producers fix the carbon dioxide which is passed through the different trophic level.
54788.Which of the following type of ecosystem is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is below 100mm
Grassland
Shrubby forest
Desert
Mangr
Explanation:
In true desert biome rainfall is less than 50cm/year, characterised by extremely hot days and cold nights. Evaporation from true desert always exceeds the precipitation (rainfall). On the other hand, grassland ecosystemreceives medium rain fall ranging from 25-75 cm/yr, but evaporation rate is not higher than precipitation rate.Shrubby forest receives rainfall 90-150cm/yr.Mangrove forests receive annual rainfall ranging from 100 -150 cm/yr. Thus, these options are wrong.
In true desert biome rainfall is less than 50cm/year, characterised by extremely hot days and cold nights. Evaporation from true desert always exceeds the precipitation (rainfall). On the other hand, grassland ecosystemreceives medium rain fall ranging from 25-75 cm/yr, but evaporation rate is not higher than precipitation rate.Shrubby forest receives rainfall 90-150cm/yr.Mangrove forests receive annual rainfall ranging from 100 -150 cm/yr. Thus, these options are wrong.
54789.Edaphic factor refers to
water
soil
relative humidity
altitude
Explanation:
Edaphic factor refers to the physical or chemical composition of the soil found in a particular area. Water, relative humidity and altitude are other abiotic components of an ecosystem but affects the climatic conditions hence are climatic factors.
Edaphic factor refers to the physical or chemical composition of the soil found in a particular area. Water, relative humidity and altitude are other abiotic components of an ecosystem but affects the climatic conditions hence are climatic factors.
54790. The zone at the edge of a lake or ocean which is alternatively exposed to air and immersed in water is called
pelagic zone
benthic zone
lentic zone
littoral zone
Explanation:
The littoral zone is the zone at the edge of a lake or ocean or in aquatic habitat which is alternatively exposed to air, hence, light is also available and immersed in water.Pelagic zone: Any zone of water in a sea or lake that is neither close to bottom nor the shore is pelagic zone.Benthic zone: It is the bottom part of the water body. Light is not available here and it is dark. Microorganisms and benthic organisms are found in this zone.Lentic zone: Itrefers to standing or relatively still water in an aquatic ecosystem.
The littoral zone is the zone at the edge of a lake or ocean or in aquatic habitat which is alternatively exposed to air, hence, light is also available and immersed in water.Pelagic zone: Any zone of water in a sea or lake that is neither close to bottom nor the shore is pelagic zone.Benthic zone: It is the bottom part of the water body. Light is not available here and it is dark. Microorganisms and benthic organisms are found in this zone.Lentic zone: Itrefers to standing or relatively still water in an aquatic ecosystem.
54791.
Which of the following is an ecosystem service provided by a natural ecosystem?
Cycling of nutrients
Prevention of soil erosion
Pollutant absorption and reduction of the threat of global warming
All of the above
Explanation:
A natural ecosystem maintains its biotic and abiotic factors naturally. The products of ecosystem processes are called the ecosystem services. The various ecosystem services provided by a natural ecosystem include: (i)Purify air and water.(ii)Migration of droughts and floods(iii)Nutrient cycling(iv)Generation of fertile soil(v)Maintenance of biodiverstity(vi)Provide storage site for carbon(vii)Pollinate crops(viii) Also provides aesthetic, cultural and spiritual valves Thus, all the above options are correct.
A natural ecosystem maintains its biotic and abiotic factors naturally. The products of ecosystem processes are called the ecosystem services. The various ecosystem services provided by a natural ecosystem include: (i)Purify air and water.(ii)Migration of droughts and floods(iii)Nutrient cycling(iv)Generation of fertile soil(v)Maintenance of biodiverstity(vi)Provide storage site for carbon(vii)Pollinate crops(viii) Also provides aesthetic, cultural and spiritual valves Thus, all the above options are correct.
54793.Plants reproducing by spores such as mosses and ferns are grouped under the general term
Cryptogams
Bryophytes
Sporophytes
Thallophytes
54796.Hetrospory is production of
Haploid and Diploid spores
sexual and asexual spores
Large and small spores
Diploid and tetraploid spores