Ecosystem Flashcards
An ______ can be visualised as a functional unit of nature, where living organisms interact among themselves and also with the surrounding physical environment
Ecosystem
Ecosystems are divided into two basic categories, namely:
Terrestrial and aquatic
Examples of terrestrial ecosystem are:
Forest, grassland and desert
Pond, Lake, weland, river and estuary are included in which category of ecosystem?
Aquatic
Name two man-made ecosystems
Crop fields and aquarium
Transfer of energy in an ecosystem occurs through _______ and ______
Food chains/webs; nutrient cycling
Interaction of ______ and ______ components result in a physical structure that is characteristic for each type of ecosystem
Biotic; abiotic
Vertical distribution of different species occupying different levels is called?
stratification
_______ occupy top vertical strata or layer of a forest
trees
Bottom vertical strata of a forest is occupied by ______ and _____
Herbs; grasses
The abiotic components of a pond are _____ and ____
Water; soil
Phytoplanktons, algae and plants are the ____ components of the pool
autotropic
_______ is a consumer of the pond ecosystem
Zooplankton
The decomposers of the pond ecosystem are _____, ______ and _______
Fungi; bacteria; flagellates
In an ecosystem, inorganic material is converted into organic material with the help of ______ energy of the sun by the autotroph
radiant
In an ecosystem, _____ are consumed by heterotroph
autotrophs
There is unidirectional movement of energy towards the _____ trophic levels in an ecosystem
higher
Constant input of which energy is the basic requirement for any ecosystem to function and sustain is
Solar energy
The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called :
Primary production
Primary production is expressed in terms of:
Weight(gm^-2) or energy (kcal m^-2)
The rate of biomass productivity is called:
productivity
Productivity is expressed in terms of:
gm^-2 yr^-1 or (kcal m^-2)yr^-1
_________ productivity of an ecosystem is the rate of production of organic matter during photosysnthesis
Gross primary productivity (GPP)
Gross primary productivity minus respiratory losses is equal to
Net primary productivity (NPP)
______ productivity is the available biomass for the consumption of heterotrophs
Net primary productivity (NPP)
The rate of formation of new organic matter by consumers is called?
Secondary productivity
The annual net primary productivity of the whole biosphere is approximately _____ tons (dry weight) of organic matter
170 billion tons
The productivity of the oceans in biosphere are only _____ tons
55 billion tons
_______ help in thr breakdown of complex organic matter as well as in loosening of the soil
Earthworms
Decomposers breakdown complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process I’d called?
decomposition
The raw material for decomposition is called:
detritus
The important steps in the process of decomposition are:
Fragmentation, leaching, catabolism, humification and mineralisation
The process of breaking down detritus into smaller particles is called:
fragmentation
The process by which water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts is called?
Leaching
During the process of catabolism in decomposition, detritus is degraded into simpler inorganic substances by ______ and ______
Bacterial; fungal enzymes
During decomposition, fragmentation, leaching and catabolism take place on:
detritus
Humification and mineralisation occur during decomposition in the _____
soil
Humification leads to accumulation of dark coloured amorphous substances called:
humus
Humus is highly resistant to _____ action
microbial
Humus serves as a reservoir of nutrients due to its ____ nature
colloidal
The humus is degraded by microbes and inorganic nutrients are released by the process known as
mineralisation
Atmospheric gas required for decomposition is:
oxygen
The rate of decomposition is controlled by chemical composition of _____ and climatic factors
detritus
In a particular climatic condition, decomposition rate is slower if detritus is rich in ____ and _____
Lignin; chitin
In a particular climatic condition, decomposition rate is quicker if detritus is rich in ____ and _____
Nitrogen; water-soluble substances (such as sugar)
The two most important climatic factors that regulate the process of decomposition are:
Temperature and soil moisture
Warm and moist environment _____ the rate of decomposition
increases
Low temperature and _____ inhibit the process of decomposition
anaerobiosis
Which part of the incident solar radiation is captured by autotrophs?
Photosynthetically active radiation (PAR)
Plants capture only _____ of Photosynthetically active radiation (PAR)
2% to 10%
The green plant in the ecosystem are called:
producers
In a ______ ecosystem, major producers are herbaceous and woody plants
terrestial
Major producers of aquatic ecosystem are various species like ___, ____ and ____
Phytoplankton; algae and higher plants
Food chains/ webs are formed because of the _____ of food among organism
interdependency
Death of organism is the beginning of the ____ food chain/ web?
Detritus food chain/ web
When animals consume plants directly, they are called ___ consumers.
primary
When animals eat other animals which in turn eat the plants, they are called ______ consumers
Secondary consumers
______ are some common herbivores of aquatic system
Molluscs
Animals that depend on the primary carnivores for food are called?
Secondary carnivores
The consumers that feed on herbivores are called ______ carnivores but ______ consumers
Primary; secondary
________ organisms are decomposers in terms of mode of nutrition?
Heterotropic organism
Decomposers are also known as :
Saprotrophs
In a terrestrial ecosystem, a much larger fraction of energy flows through the detritus food chain than through the ______
Grazing food chain
Some of the organisms of _______ are prey to the _____ animals.
Detritus food chain; Grazing food chain
In a natural ecosystem, some animals like cockroaches, are omnivores. These natural interconnection of food chains make it a _________
Food web
Based on the source of their nutrition or food, organism occupy a specific place in the food chain that is known as their ______
Tropic level
_________ belongs to first tropic level
Producers
________ belongs to the first tropic level, _____ to the second and ______ to the third .
Producers; herbivores; Carnivores
The amount of energy _______ at successive tropic levels
decreases
Each tropic level has a certain mass of living material at a particular time called as the:
Standing crop
The biomass of a species is expressed in terms of fresh or _______
Dry weight
Only ____ per cent of the energy is transferred to each tropic level from the lower tropic level
10 per cent
Food and energy relationship between organism is expressed in terms of ______, ______ or _____
Number; biomass; energy
The base of each pyramid represents the _____
producers
The base of a pyramid is broad and it narrows towards the ______
apex
Energy at a lower tropic level of a food chain is always ______ than at a higher tropic level
more
The pyramid of biomass in ____ is inverted
sea
Pyramid of biomass in sea is inverted because biomass of _____ exceeds that of phytoplanktons
fishes
Pyramid of ____ is always upright
energy
Which pyramid does not take into account food webs?
Ecological
The organisms which are not given any place in ecological pyramids are:
saprophytes
Sequential changes with changes in physical environment leads to a community that is in near equilibrium with the environment and that is known as:
Climax community
The gradual and predictable changes in the species composition of a given area is called:
Ecological succession
The entire sequence that successively change in a given area are called?
Sere(s)
The individual transitional communities involved in ecological succession are called:
Seral stages/communities
The succession that starts in an areas where living organisms never existed is called:
Primary succession
The succession that starts in areas that somehow, lost all of its living organisms is called:
Secondary succession
Examples of areas where primary succession occurs are:
Newly cooled lava, bare rock, newly created pond or reservoir
The establishment of a new ______ community is generally slow
Biotic community
_____ succession begins in area where natural biotic communities have been destroyed.
Secondary
_______ succession occurs faster than _____ succession
Secondary; primary
During succession, _____ or _____ disturbances can convert a particular seral stage of succession to an earlier stage
Natural; human induced
______ succession takes place in wet areas
Hydrarch succession
During hydrarch succession, the successional series progress from hydric to the ____ conditions
mesic
______ succession takes place in dry areas
Xerarch succession
During xerarch succession, the successional series progress from xeric to _____ conditions
mesic
The species that invade a bare area are called?
Pioneer species
In primary succession on rocks these are usually ______ which are able to secreted acids to dissolve rocks
lichens
During primary succession of rocks, some small plants that appear to take hold of the soil are:
bryphytes
Climax community formed during primary succession on rocks is:
Forest community
In primary succession in water, the pioneer are the small ______
phytoplanktons
Climax community during primary succession in water is:
forest
During primary succession in water, free-floating plants are replaced by ______, followed by ____, _______ and tress
Reed-swapy; marsh-meadow; scrub
All succession whether taking place in water or on land, proceeds to a similar climax community-
The mesic
The amount of nutrients, such as carbon, nitrogen, etc., present in the soil at any given time, is referred to as the ______ state
Standing state
The movement of nutrient elements through the various components of an ecosystem is called?
Nutrient cycling
Nutrient cycling is of two types:
Gaseous and sedimentary
______ is the reservoir for the gaseous type of cycle
Atmosphere
Name two gaseous type of nutrient cycles
Nitrogen and carbon cycle
Name two sedimentary cycles
Sulphur and phosphorus cycle
Environmental factors, e.g., ______, ______, ______, ______, etc., regulate the rate of release of nutrients into the atmosphere
Soil, moisture, pH, temperature
Carbon constitutes _____ percent of dry weight of organism
49
_____ percent carbon is found dissolved in oceans.
71%
The reservoir which regulates the amount of carbon dioxide in atmosphere is:
Ocean reservoir
______ kg of carbon is fixed annually in the biosphere through photosynthesis
4 * 10^13
According to one estimate 4 * 10^13 kg of carbon is fixed annually in the biosphere through _______
photosynthesis
A considerable amount of carbon returns to the atmosphere as CO2 through ______ activities of the producers and consumers
respiratory
Burning of wood, forest fire and combustion of organic matter, fossil fuel, volcanic activity are additional sources for releasing ______ in the atmosphere
Carbon dioxide
________ is a major constituent of biological membranes, nuclei acids and cellular energy transfer systems
Phosphorus
The natural reservoir of phosphorus is:
rock
Rocks contains phosphorus in the form of:
phosphorus
Herbivores and other animals obtain phosphorus from:
plants
The waste products and the dead organisms are decomposed by ______ bacteria releasing phosphorus
phosphate-solubilising
Robert Constanza and his colleagues have put an average price tag of US $ _______ a year on fundamental ecosystem services
33 trillon
Mark A, B and C in the following diagram.
A) food web; B) leach; C) decomposition
Mark A, B, C and D in the following diagram.
A) Tertiary consumer;
B) Birds, fishes, wolf;
C) Primary consumer;
D) Phytoplankton, grass, trees
Mark A, B, C and D in the following diagram.
A) Plants;
B) Herbivores;
C) Carnivores;
D) Top carnivores
Identify the type of pyramid in a grassland ecosystem in the figure
Pyramid of numbers
Identify the type of pyramid in the figure
Pyramid of biomass
Identify the type of pyramid in the figure
Pyramid of energy
Mark A, B, C , D and E in the following figure
A) Phytoplankton;
B) Reed-swamp stage;
C) Submerged plant stage;
D) Scrub stage;
E) Forest
Mark A, B, C, D, E and F in the following cycle
A) Limestone and dolomite;
B) Detritus food chain;
C) Coal;
D) CO2 in atmosphere;
E) Photosynthesis;
F) Calcereous sediments
Mark A, B, C, D and E in the following figure
A) Consumers;
B) Detritus;
C) Decomposition;
D) Weathering;
E) Rock minerals
