1382 + Interview Questions in ECOSYSTEM IN GENERAL AWARENESS Page 7 InterviewSolution

301.	In ecological succession from pioneer to climax community, the biomass shallA. DecreaseB. Increase and then decreaseC. No relationD. Increase continuously
Answer» Correct Answer - D

Discussion

302.	Assertion (A) : In a food chain members of successive higher levels are fewer in number. Reason (R ): Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - A Each food chain contains many steps like producers, herbivores, primary carnivores and so on. Each step of the food chain is called trophic level. Number of organisms at any trophic level depends upon the avilability of food. In grassland ecosystem the maximum number of organisms are found in lower tropic level but in forest ecosyystem and parasitic food chain it is reverse.

Discussion

303.	Phytoplanktons areA. HeterotrophsB. AutotrophsC. SaprotrophsD. All of these
Answer» Correct Answer - B

Discussion

304.	Assertion (A) : A network of food chains existing together in an ecosystem is known as a food web. Reason (R ) : An animal-like kite cannot be a part of a food web.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - C

Discussion

305.	Assertion : Ecological pyramids are also called Eltonian pyramids. Reason : An ecological pyramid is always upright.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - C Ecological pyramids were developed by Charles Elton and are, therefore, also called Eltonian pyramids. An ecological pyramid can be upright, inverted or spindle shaped depending upon criteria of formation of pyramid(like energy, biomass or number) and the type of food chain involved parasitic, apuatic or terrestrial.

Discussion

306.	Animals which occupy the same trophic levelA. Tiger and bearB. Deer and beesC. Snake and earthwormD. Crow and cow
Answer» Correct Answer - B

Discussion

307.	Assertion : Lichens and mosses are said to form the pioneer community in xerarch succession. Reason : It is because these species get established later, during the course of succession.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - C The plants that invade the base land initially, are called pioneer community. Lichens and mosses form the pioneer community in xerarch succession species. The assemblage of pioneer species forms the pioneer. Lichens form a crust over the base rocks and begin to form soil from their organic remains and by stimulating chemical breakdown of the rocks. Lichens are normally followed by mosses, which speed uyp the process of soil accumulation by trapping wind blown particles. Mosses grow in bunch, and together with lichens, and mosses get establishedon barren rock as pioneer species forming the pioneer community. Generally, the pioneer species show high rate of growth but short life span. In time, the pioneer community is replacedby another community with different species combination. This second communtiy is replaced by a third community, and so on. The plant species which get established later, during the course of succession, are known as late successional species. These species are slow growing and long lived. The terminal stage of succession is represented by the climax community which is stable and does not show change in species composition, as long as the environmental conditions remain the same.

Discussion

308.	Find out the correct order of succession levels in XerarchA. Lichen moss stage, Annual herb stage, Perennial herb stage, Scrub stage, ForestB. Annual herb stage, Perennial herb stage, Lichen moss stage, Scrub stage, ForestC. Perennial herb stage, Annual herb stage, Perennial Scrub Stage, Lichen moss stageD. Forest, Scrub stage, Annual herb stage, Perennial herb stage, Lichen moss stage,
Answer» Correct Answer - A

Discussion

309.	Which atom is limiting the primary productivity mostlyA. CB. PC. DD. N
Answer» Correct Answer - A

Discussion

310.	Assrtion : The rate of decomposition of detritus is reduced in the regions of high altitude. It happens due to immobilisation of nutrientsA. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - C At high altitude, the temperature becomes very low `(lt 10^(@)C)`. It greatly reduces the activity of microbes, principal decomposers. Nutrients immobilisation means tiding up of nutrients material with the biomass of microbes. This immobilisation prevents the nutrients from being washed out from the ecosystem.

Discussion

311.	`Y-`shaped energy flow models haveA. Single channelB. Two channelsC. Three channelsD. None of these
Answer» Correct Answer - B

Discussion

312.	Thermocline exists between hypolimnion and epilimnion. Reason : Thermocline acts as a barrier between hypolimnion and epilimnion. Reason : Thermocline acts as a barrier between the two layers.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - A The warner upper part of the lake or epilimnion becomes temporarily isolated from the colder lower water or hypolimnion by a thermocline zone (temperature stratification) that acts as a barrier to exchange of materials. Consequently. The supply of oxygen in the hypolimnion and nutrients in the epilimnion may run short.

Discussion

313.	Psammophytes are plants that grow where soil isA. AlkalineB. SandyC. AcidicD. Alluvial
Answer» Correct Answer - B

Discussion

314.	Study the four statement (i-iv) given below and select the two correct ones out of them (i) A lion eating a deer and a sparrow feeding or grains are ecologically similar in being consumers. (ii) Predator star fish Pisaster helps in maintaining species diversity of some invertebrates (iii) Predators ultimately lead to the extinction of prey species (iv) Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders The two correct statements areA. (A) and (B)B. (B) and (C)C. (C) and (D)D. (A) and (D)
Answer» Correct Answer - A

Discussion

315.	The abyssal zone of oceans is characterized by:A. Presence of sunlight and producersB. Absence of sunlight and all living organismsC. Absence of sunlight but presence of producersD. Absence of sunlight and presence of consumers and decomposers
Answer» Correct Answer - D Abyssal zone is a dark zone.

Discussion

316.	Assertion : Ecotone shows more diversity. Reason : Ecotone is an sharp transition zone between two or more diverse communities.A. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - A A sharp transition between two or more diverse communities, for example, forest and grassland, is known as ecotone. The ecotonal community commonly contains many of the organisms of each of the overlapping communities and in addition, organisms characteristic of and oftern restricted to ecotone. The tendency for increased variety and density at community junctions is known as the edge effect.

Discussion

317.	Both, hydrarch and xerarch successions lead toA. Highly dry conditionsB. Excessive wet conditionsC. Medium water conditionsD. Xeric conditions
Answer» Correct Answer - C

Discussion

318.	All type of successions leads toA. xeric climax community qB. hydric climax communityC. mesic climax communityD. any climax community depending on nature of habitat.
Answer» Correct Answer - C All type of successions wheather taking place in water or on land, proceeds to a similar climax community, i.e., mesic.

Discussion

319.	Successions that occur on soils or areas which have recently lost their community are reffered to asA. primary successionsB. secondary successionsC. lithoseresD. priseres.
Answer» Correct Answer - B Secondary succession (=subsere) is the biotic succession that occurs in an area which become secondarily bare due to the destruction of community previously present there. Secondary succession starts from previously built up substrata with already existing living matter. the action of any external force, such as a sudden change in climatic factors, biotic intervention, fire, etc. had resulted in the destruction of previous community. Thus, area became devoid of living matter. The action of any external force, such as a sudden change in climatic fators, biotic intervention, fire etc. had resulted in the destruction or previous comunity. Thus, area became devoid of living of previous community. Thus, area became devoid of living matter but its substratum, instead of primitive, is built up. It has organic matter so is biologically fertile and thus, the successions are comparatively more rapid.

Discussion

320.	Differentiate between primary and secondary ecological successions.
Answer» Primary succession: It begins in areas where no living organisms ever existed. Therefore, the establishment of a biotic community is very slow, e.g., newly cooled lava, bare rock, newly created pond or reservoir. Secondary succession: It begins in areas where natural biotic communities have been destroyed, e.g., abandoned farm lands, buried or cut forests. Since soil is available, it is a faster process.

320.

Differentiate between primary and secondary ecological successions.

Answer»

Primary succession: It begins in areas where no living organisms ever existed. Therefore, the establishment of a biotic community is very slow, e.g., newly cooled lava, bare rock, newly created pond or reservoir.

Secondary succession: It begins in areas where natural biotic communities have been destroyed, e.g., abandoned farm lands, buried or cut forests. Since soil is available, it is a faster process.

Discussion

321.	Explain the different steps of xerarch succession occurring in nature.
Answer» Xerarch Succession in Nature: • Lichens are the pioneer species on a bare area. • The lichen secretes some acids to dissolve rock and help in weathering and soil formation. • Later, some small bryophytes invade and hold the small amount of soil. • The bryophytes are succeeded by herbs, shrubs and ultimately big trees. • At last, a stable climax forest is formed. • The xerophytic habitat gets converted into a mesophytic one.

321.

Explain the different steps of xerarch succession occurring in nature.

Answer»

Xerarch Succession in Nature:

• Lichens are the pioneer species on a bare area.

• The lichen secretes some acids to dissolve rock and help in weathering and soil formation.

• Later, some small bryophytes invade and hold the small amount of soil.

• The bryophytes are succeeded by herbs, shrubs and ultimately big trees.

• At last, a stable climax forest is formed.

• The xerophytic habitat gets converted into a mesophytic one.

Discussion

322.	Why are nutrient cycles in nature called biogeochemical cycles?
Answer» Nutrient cycles are called biogeochemical cycles because ions/molecules of a nutrient aye transferred from the environment (rocks, air and water) to organisms (life) and then brought back to the environment in a cyclic pathway. The literal meaning of biogeochemical is bioliving organism and georocks, air and water.

Discussion

323.	i. Name the biogeochemical (nutrient) cycle shown above. ii. Name an activity of the living organisms not depicted in the cycle by which this nutrient is returned to the atmosphere.
Answer» i. The biogeochemical cycle shown is carbon cycle. ii. Volcanic activity and mining/Microbial decomposition of organic matter.

323.

i. Name the biogeochemical (nutrient) cycle shown above. ii. Name an activity of the living organisms not depicted in the cycle by which this nutrient is returned to the atmosphere.

Answer»

i. The biogeochemical cycle shown is carbon cycle.

ii. Volcanic activity and mining/Microbial decomposition of organic matter.

Discussion

324.	How would the flow of the nutrient in the cycle be affected due to large scale deforestation? Explain giving reasons.
Answer» Due to large scale deforestation, the flow of carbon in the environment will be disturbed because plants are the major consumers which utilise carbon for photosynthesis. This would lead to accumulation of carbon in the atmosphere.

Discussion

325.	Consider the following four statements (A-D) and select the correct option stating which ones are true (T) and which ones are False (F). (A) Vertical distribution of different species occupying different levels in a community is called stratification. (B) Net primary productivity minus respiration losses is the gross primary productivity. (C) Rate of biomass production is called decompostion. (D) Annual net primary productivity of oceans is 55 billion tons.A. `{:(" "(A),(B),(C),(D)),((1)" "F,T,F,T):}`B. `{:(" "(A),(B),(C),(D)),((2)" "T,F,T,F):}`C. `{:(" "(A),(B),(C),(D)),((3)" "T,F,F,T):}`D. `{:(" "(A),(B),(C),(D)),((4)" "F,T,F,F):}`
Answer» Correct Answer - A

Discussion

326.	Nitrogen is fixed throughA. atmosphericB. industrialC. biologicalD. All of these
Answer» Correct Answer - D

Discussion

327.	Area where two ecosystem overlap each other:A. nicheB. ecotoneC. ecotypeD. edge line
Answer» Correct Answer - B

Discussion

328.	The boundary or transition between two or more communities which are sharply defined is called:A. BiomeB. EcotypeC. EcotoneD. Thermocline
Answer» Correct Answer - C

Discussion

329.	Succession is the characteristic ofA. EcosystemB. CommunityC. PopulationD. Organism
Answer» Correct Answer - B Succession is the characteristic of community.

Discussion

330.	The sequence of communities of primary succession in water isA. phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and tressB. phytoplankton, free floating hydrophysis, rooted hydrophytes, sedges, grasses and treesC. free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and treesD. phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.
Answer» Correct Answer - D Primary succession in water is also called as hyrarch, which will lead from hydric to mesic conditions. Phytoplanktons (autotrophic) are generally the first to appear. Later zooplanktons fedding on phytoplanktons also appear. Next stage is characterised by the soft mud on the bottom having organic matter favouring the growth of rooted submerged plants. They are then replaced by free floating hydrophytes (Lemna, Wolffia etc.). Rapid growth of these plants build up bottom so that water becomes shallow on periphery. In this shallow water, comes the reed-swamp stage (e.g., Typha). They produce abundant organic matter. Next stages are sedge or marsh-meadow stage which transpire rapidly and build up soil, on which the next stage, (trees) can grow.

Discussion

331.	The sequence of communities of primary succession in water isA. Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and trees.B. Phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses and trees. C. Free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and trees.D. Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.
Answer» Correct Answer - d The sequences of communities of primary succession in hydrosere is phytoplankton (pioneer stage) `to` rooted submerged hydrophytes `to` floating hydrophyte (floating stage) `to` reed swamp `to` sedges `to` meadow and woodland (trees). The other options are wrong.

Discussion

332.	A place was rocky and barren but now, there is a green forest, the sequence of origin is:A. lichen. Moss, herbs, shrubsB. moss, lichen, herbs, shrubsC. lichen, moss, shrubs, herbsD. shrub, herbs, moss, lichen
Answer» Correct Answer - A

Discussion

333.	Both algae and fungi are not independently capable of initiating seral changes on bare rocks but lichens can do so becase theyA. Adapt suitably to mesic conditionsB. Are a combination of alge and fungiC. Can secrete acids for weatheringD. Do not require much sunlight
Answer» Correct Answer - C

Discussion

334.	The present day communities in the world have come to be because ofA. EvolutionB. SuccessionC. VariationD. Mutation
Answer» Correct Answer - B The present day communities in the world have come to be because of succession that occurred over millions of years since life started on earth.

Discussion

335.	The sequence of communities of primary succession in water isA. phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and treesB. phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses and treesC. free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and treesD. phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees
Answer» Correct Answer - D

Discussion

336.	During succession , in the successive seral stages , there is a/anA. Change in the diversity of species of organsimsB. Increase in the number of species and organismsC. Increase in the total biomassD. All of the above
Answer» Correct Answer - D During succession, in the successive seral stages there is a change in the diversity of species of organisms , increase in the number of species and organisms and increase in the total biomass.

Discussion

337.	The entire sequence of communities that succesively change in a given area are calledA. Seral stagesB. Pioneer communityC. Climax communityD. Sere (s)
Answer» Correct Answer - D The entire sequence of communities that successively change in a given area are called sere(s).

Discussion

338.	Pyramid of numbers deals with number ofA. Species in an areaB. Individuals in a communityC. Individuals in a trophic levelD. Subspecies in a community
Answer» Correct Answer - C Pyramid of numbers deals with number of individuals in a trophic level.

Discussion

339.	An inverted pyramid of biomass can be found in which ecosystemA. ForestB. MarineC. GrasslandD. Tundra
Answer» Correct Answer - B An inverted pyramid of biomass can be found in marine ecosystem.

Discussion

340.	Pyramid of number isA. Always uprightB. Always invertedC. Either upright or invertedD. Neither upright nor inverted
Answer» Correct Answer - C `` Pyramid of number in grassland or forest or pond ecosystem is upright . `` In parasitic food chain, the pyramid of number is inverted.

Discussion

341.	In parasitic food chain, the pyramid of number isA. linearB. uprightC. invertedD. inverted upright
Answer» Correct Answer - C

Discussion

342.	(a) Explain primary productivity and the factors that influence it. (b) Describe how oxygen and chemical composition of detritus control decomposition.
Answer» (a) Primary productivity : amount of biomass / organic matter produced per unit area over a time period by the plant during photosynthesis. Factors : availability of nutrients / quality of light available / availability of water / temperature of the given place / type of plant species of the area / photosynthetic capacity of the plants. (b) Oxygen increases rate of decomposition. Decomposition is an oxygen consuming Process. It takes place under aerobic conditions i.e., in presence of oxygen. Chemical decomposition is slow when chitin and lignin are present and fast when cellulose and water soluble substances are present.

342.

(a) Explain primary productivity and the factors that influence it. (b) Describe how oxygen and chemical composition of detritus control decomposition.

Answer»

(a) Primary productivity : amount of biomass / organic matter produced per unit area over a time period by the plant during photosynthesis.

Factors : availability of nutrients / quality of light available / availability of water / temperature of the given place / type of plant species of the area / photosynthetic capacity of the plants.

(b) Oxygen increases rate of decomposition.

Decomposition is an oxygen consuming Process. It takes place under aerobic conditions i.e., in presence of oxygen.

Chemical decomposition is slow when chitin and lignin are present and fast when cellulose and water soluble substances are present.

Discussion

343.	In an ecosystem,A. Primary producers are more than primary consumersB. Primary consumers are larger than primary producersC. Secondary consumers are larger than primary producersD. Primary consumers least depend on primary producers
Answer» Correct Answer - A

Discussion

344.	Energy enters in food chain byA. ProducerB. Primary consumersC. Secondary consumersD. Tertiary consumers
Answer» Correct Answer - A

Discussion

345.	The term biocoenosis was given byA. HaeckelB. Carl MobiusC. TansleyD. Odum
Answer» Correct Answer - B The term biocoenosis was given by Carl Mobius.

Discussion

346.	Concept of life forms was given byA. TansleyB. ClementsC. RaunkierD. Odum
Answer» Correct Answer - C Concept of life forms was given by Raunkier.

Discussion

347.	Ecosystem of pond isA. LoticB. LenticC. BenthicD. Xeric
Answer» Correct Answer - B Ecosystem of a pond is lentic (standing water).

Discussion

348.	Humus is formed inA. O-horizonB. A-horizonC. B-horizonD. C-horizon
Answer» Correct Answer - A Humus is formed in O-horizon.

Discussion

349.	Bulk `CO_(2)`fixation occurs inA. Crop plantsB. OceansC. Tropical rain forestsD. Temperate forests
Answer» Correct Answer - B Bulk `CO_(2)` fixation occurs in oceans.

Discussion

350.	Xeric environment is characterised byA. PrecipitationB. Low atmospheric humidityC. Extreme of temperatureD. Extreme of temperature
Answer» Correct Answer - B Xeric environment is characterised by low atmospheric humdity. This environment is found in deserts.

Discussion

Explore topic-wise InterviewSolutions in .

In ecological succession from pioneer to climax community, the biomass shallA. DecreaseB. Increase and then decreaseC. No relationD. Increase continuously

Phytoplanktons areA. HeterotrophsB. AutotrophsC. SaprotrophsD. All of these

Animals which occupy the same trophic levelA. Tiger and bearB. Deer and beesC. Snake and earthwormD. Crow and cow

Which atom is limiting the primary productivity mostlyA. CB. PC. DD. N

`Y-`shaped energy flow models haveA. Single channelB. Two channelsC. Three channelsD. None of these

Psammophytes are plants that grow where soil isA. AlkalineB. SandyC. AcidicD. Alluvial

The abyssal zone of oceans is characterized by:A. Presence of sunlight and producersB. Absence of sunlight and all living organismsC. Absence of sunlight but presence of producersD. Absence of sunlight and presence of consumers and decomposers

Both, hydrarch and xerarch successions lead toA. Highly dry conditionsB. Excessive wet conditionsC. Medium water conditionsD. Xeric conditions

All type of successions leads toA. xeric climax community qB. hydric climax communityC. mesic climax communityD. any climax community depending on nature of habitat.

Successions that occur on soils or areas which have recently lost their community are reffered to asA. primary successionsB. secondary successionsC. lithoseresD. priseres.

Differentiate between primary and secondary ecological successions.

Explain the different steps of xerarch succession occurring in nature.

Why are nutrient cycles in nature called biogeochemical cycles?

i. Name the biogeochemical (nutrient) cycle shown above. ii. Name an activity of the living organisms not depicted in the cycle by which this nutrient is returned to the atmosphere.

How would the flow of the nutrient in the cycle be affected due to large scale deforestation? Explain giving reasons.

Nitrogen is fixed throughA. atmosphericB. industrialC. biologicalD. All of these

Area where two ecosystem overlap each other:A. nicheB. ecotoneC. ecotypeD. edge line

The boundary or transition between two or more communities which are sharply defined is called:A. BiomeB. EcotypeC. EcotoneD. Thermocline

Succession is the characteristic ofA. EcosystemB. CommunityC. PopulationD. Organism

A place was rocky and barren but now, there is a green forest, the sequence of origin is:A. lichen. Moss, herbs, shrubsB. moss, lichen, herbs, shrubsC. lichen, moss, shrubs, herbsD. shrub, herbs, moss, lichen

Both algae and fungi are not independently capable of initiating seral changes on bare rocks but lichens can do so becase theyA. Adapt suitably to mesic conditionsB. Are a combination of alge and fungiC. Can secrete acids for weatheringD. Do not require much sunlight

The present day communities in the world have come to be because ofA. EvolutionB. SuccessionC. VariationD. Mutation

During succession , in the successive seral stages , there is a/anA. Change in the diversity of species of organsimsB. Increase in the number of species and organismsC. Increase in the total biomassD. All of the above

The entire sequence of communities that succesively change in a given area are calledA. Seral stagesB. Pioneer communityC. Climax communityD. Sere (s)

Pyramid of numbers deals with number ofA. Species in an areaB. Individuals in a communityC. Individuals in a trophic levelD. Subspecies in a community

An inverted pyramid of biomass can be found in which ecosystemA. ForestB. MarineC. GrasslandD. Tundra

Pyramid of number isA. Always uprightB. Always invertedC. Either upright or invertedD. Neither upright nor inverted

In parasitic food chain, the pyramid of number isA. linearB. uprightC. invertedD. inverted upright

(a) Explain primary productivity and the factors that influence it. (b) Describe how oxygen and chemical composition of detritus control decomposition.

In an ecosystem,A. Primary producers are more than primary consumersB. Primary consumers are larger than primary producersC. Secondary consumers are larger than primary producersD. Primary consumers least depend on primary producers

Energy enters in food chain byA. ProducerB. Primary consumersC. Secondary consumersD. Tertiary consumers

The term biocoenosis was given byA. HaeckelB. Carl MobiusC. TansleyD. Odum

Concept of life forms was given byA. TansleyB. ClementsC. RaunkierD. Odum

Ecosystem of pond isA. LoticB. LenticC. BenthicD. Xeric

Humus is formed inA. O-horizonB. A-horizonC. B-horizonD. C-horizon

Bulk `CO_(2)`fixation occurs inA. Crop plantsB. OceansC. Tropical rain forestsD. Temperate forests

Xeric environment is characterised byA. PrecipitationB. Low atmospheric humidityC. Extreme of temperatureD. Extreme of temperature