Ecosystem Flashcards
(142 cards)
1
Q
An ecosystem can be visualised as a — of nature, where living organisms —- and also with the —- .
A
functional unit
interact among themselves
surrounding physical environment
2
Q
Ecosystem varies greatly in — from a —- to a large forest or a sea.
A
size
small pond
3
Q
Many ecologists regard the entire biosphere as a —-, as a composite of all
—- on Earth.
A
global ecosystem
local ecosystems
4
Q
Since this system is too much — and —- to be studied at one time, it is convenient to divide it into two basic categories, namely the —- and —-.
A
big and complex
terrestrial and the aquatic
5
Q
Forest, — and — are some examples of terrestrial ecosystems; pond, lake, —- , — and —are some examples of aquatic ecosystems.
A
grassland, desert
WETLAND, river and estuary
6
Q
—- and —- may also be
considered as man-made ecosystems.
A
Crop fields and an aquarium
7
Q
We will first look at the structure of the ecosystem, in order to appreciate the input (— ), —- (food chain/web, —–) and the output (— and —-).
A
productivity
transfer of energy
nutrient cycling
degradation and energy loss
8
Q
We will also look at the
relationships – —, — and — – that are created as a result of these — within the system and their inter- relationship
A
cycles, chains, webs
energy flows
9
Q
Various components of the environment- — and —.
A
abiotic and biotic
10
Q
Individual biotic and abiotic factors affected — and —.
A
each other and their surrounding
11
Q
Interaction of biotic and abiotic components result in a —-
A
physical structure
12
Q
—- is characteristic for each type of ecosystem.
A
Physical structure (produced by interaction of biotic and abiotic factors)
13
Q
— and —- of PLANT and ANIMAL species of an ecosystem gives its
—–.
A
Identification and enumeration
species composition
14
Q
— distribution of different species occupying different levels is called —.
A
Vertical
stratification
15
Q
For example, trees occupy —- or layer of a —,
— the second and —-
occupy the bottom layers.
A
top vertical strata, forest
shrubs
herbs and grasses
16
Q
The components of the ecosystem are seen to function as a — when
you consider the following aspects: —- (4)
A
unit
(i) Productivity;
(ii) Decomposition;
(iii) Energy flow; and
(iv) Nutrient cycling.
17
Q
To understand the — of an — ecosystem let us take a small pond as an example.
This is fairly a — and rather — example that explain even the — interactions that exist in an aquatic ecosystem.
A
ethos, aquatic
self-sustainable unit
simple
complex
18
Q
A pond is a —- body in which all the above mentioned — basic components of an ecosystem are well exhibited
A
shallow water
four
19
Q
The abiotic component in a small pond is the — with all the —- and —-substances and the —- at the bottom of the pond.
A
water
dissolved inorganic and organic
rich soil deposit
20
Q
The —-, the cycle of —, — and other — conditions regulate the —- of the entire pond
A
solar input
temperature
day-length
climatic
rate of function
21
Q
The — components of small pond include the —, some — and the —, — and —plants found at the edges.
A
autotrophic
phytoplankton, algae
floating, submerged and marginal
22
Q
The consumers of small pond are represented by the —, the — and —- forms.
A
zooplankton
free swimming and bottom dwelling
23
Q
The decomposers of small pond are the —, — and —- especially abundant in the — of the pond.
A
fungi, bacteria and flagellates
bottom
24
Q
This pond system performs all the functions of any — and of the — as a whole, i.e., conversion of — material with the help of the —- of the sun by the autotrophs; — by heterotrophs; decomposition and — of the dead matter to release them back
for —-, these event are repeated over and over again.
A
ecosystem, biosphere
inorganic into organic
radiant energy
consumption of the autotrophs
mineralisation
reuse by the autotrophs
25
26
There is --- movement of energy towards the --- trophic levels and its ---- and ---- to the environment.
unidirectional
higher
dissipation and loss as heat
27
A --- input of --- is the basic requirement for any ecosystem to --- and ---.
constant
solar energy
function and sustain
28
--- production is defined as the amount of --- and --produced per unit --- over a time period by PLANTS during ---
Primary
biomass or organic matter
area
photosynthesis
29
Primary production is expressed in terms of ---or ----.
weight (g/m^2) or
energy (kcal/m^2).
30
The ---- is called productivity.
rate of biomass production
31
Productivity is expressed in terms of ---- or ---- to compare the productivity of different ecosystems.
g/ (m^2 year)
kcal/ (m^2 year)
32
Productivity can be divided into --- and ----
gross primary productivity (GPP) and net primary productivity (NPP).
33
Gross primary productivity of an ecosystem is the rate of production of ---- during --- .
organic matter
photosynthesis
34
A considerable amount of GPP is utilised by plants
in --- .
respiration
35
Gross primary productivity minus respiration losses (R), is the -----
net primary productivity (NPP).
36
GPP – ? = NPP
GPP – R = NPP
37
Net primary productivity is the ---- for the consumption to heterotrophs (---)
available biomass
(herbiviores and decomposers)
38
Secondary productivity
is defined as the rate of formation of -----
new organic matter by consumers.
39
Primary productivity depends on the ---- a
particular area. It also depends on a variety of ---factors, availability of ---and --- of plants.
plant species inhabiting
environmental
nutrients
photosynthetic capacity
40
Therefore, ----- varies in different types of ecosystems
1' productivity
41
The --- NET primary
productivity of the whole biosphere is approximately ---- (----) of organic matter.
annual
170 BILLION tons (dry weight)
42
Of the 170 billion tons of NPP, despite occupying about ---- of the surface, the productivity of the oceans are only ---
Rest of course, is on land.
70 percent
55 billion tons.
43
You may have heard of the earthworm being referred to as the ----. This is so because they help in the ---- as well as in ---
farmer’s ‘friend’
breakdown of complex organic matter
loosening of the soil.
44
Similarly, decomposers break down ---- into inorganic substances like ----, --- and ---- and the process is called decomposition.
complex organic matter
carbon dioxide, water and nutrients
45
----- such as leaves, bark, flowers and dead remains of animals, including ---, constitute ----
Dead plant remains
fecal matter
detritus
46
----- is the raw material for decomposition.
Detritus
47
The important steps in the process of
decomposition are ---- (5)
fragmentation, leaching, catabolism, humification
mineralisation
48
Detritivores (Ex:----) break down detritus into ---.
This process is called ---.
e.g., earthworm
smaller particles
fragmentation
49
By the process of ---, ----nutrients go down into the ---- and get precipitated as ----
leaching
water soluble inorganic
soil horizon
unavailable salts.
50
----- enzymes degrade detritus into simpler ----. This process is called as --.
Bacterial and fungal
inorganic substances
catabolism
51
It is important to note that all the above steps (frag, leach, cata) in decomposition ---- on the detritus
operate simultaneously
52
Humification and
mineralisation occur during decomposition in the --- .
soil
53
Humification leads to accumulation of a ---- substance called ---
dark coloured amorphous
humus
54
Humus is HIGHLY resistant to---- and undergoes decomposition
at ---- rate.
highly resistant to microbial action
an extremely slow
55
Humus being --- in nature it serves as a reservoir
of ---.
colloidal
nutrients
56
The humus is further degraded by ---- and release of --- nutrients occur by the process known as ---.
some microbes
inorganic
mineralisation
57
Decomposition is largely an ---- requiring process.
oxygen-
58
The rate of decomposition is controlled by --- of detritus and ---factors.
chemical composition
climatic
59
In a particular climatic condition, decomposition rate is slower if detritus is rich in ---- and quicker, if detritus is rich in ----
lignin and chitin,
nitrogen and water-soluble substances like sugars.
60
--- and ---- are the most important climatic factors that regulate decomposition through their effects on the ----
Temperature and soil moisture
activities of soil microbes.
61
---- and ---- environment favour decomposition whereas --- and ---- inhibit decomposition resulting in ---- materials.
Warm and moist
low temperature and anaerobiosis
build up of organic
62
Except for the ---- ecosystem, --- is the only source of energy for all ecosystems on Earth.
deep sea hydro-thermal
sun
63
Of the incident solar radiation ---- of it is ---- (PAR).
less than 50 per cent
photosynthetically active radiation
64
We know that ---- and ----(autotrophs), fix ---- to make food from simple ---materials.
plants and photosynthetic bacteria
Sun’s radiant energy
inorganic
65
Plants capture only ---- of the PAR and this small amount of energy ---
2-10 per cent
sustains the entire living world.
66
So, it is very important to know how the --- captured by plants flows through different organisms of an
ecosystem.
solar energy
67
All organisms are dependent for their food on --- , either directly or indirectly.
producers
68
There is --- of energy from the --- to ---- and then to consumers.
Is this in keeping with the first law of thermodynamics?
unidirectional flow
sun to producers
69
Further, ecosystems are not exempt from the --- Law of--- . They need a constant --- to synthesise
the --- they require, to counteract the ----
Second
thermodynamics
supply of energy
molecules
universal tendency toward
increasing disorderliness.
70
The --- in the ecosystem are called producers.
green plant
71
In a terrestrial
ecosystem, major producers are --- and ---plants.
herbaceous and woody
72
Likewise, producers in an aquatic ecosystem are various species like ---, --- and ----
phytoplankton, algae and higher plants.
73
Starting from the plants (or ----) food chains or rather ---- are
formed such that an animal feeds on a plant or on another animal and in
turn is food for another.
producers
webs
74
The food chain or web is formed because of ----.
this interdependency
75
--- energy that is trapped into an organism remains in it ----.
No
for ever
76
The energy trapped by the producer, hence, is either ---- or the ---.
passed on to a consumer
organism dies
77
---- is the beginning of the detritus food chain/web
Death of organism
78
All ---- depend on plants (directly or indirectly) for their ----
They are hence called ---- and also ----
animals
food needs
consumers and also heterotrophs.
79
If the consumers feed on
the producers, the plants, they are called ---, and if the animals eat other animals which in turn eat the plants (----) they are called ----
Likewise, you could have tertiary consumers too.
primary consumers
or their produce
secondary consumers.
80
Obviously the primary consumers will be ---.
herbivores
81
Some common herbivores are ----, --- and ---- in terrestrial ecosystem and ---- in aquatic ecosystem
insects, birds and mammals
molluscs
82
The consumers that feed on these herbivores are ---, or more correctly ---- (though ---consumers).
carnivores
primary carnivores
secondary
83
Those animals that depend on the primary carnivores for food are labelled ---
secondary carnivores.
84
A simple --- food chain (GFC) is depicted
below
grazing
Grass ---> Goat ----> Man
85
The detritus food chain (DFC) begins with ----
dead organic matter
86
Detritus food chain is made up of decomposers which are ----, mainly -- and ---.
heterotrophic organisms
fungi and bacteria
87
Decomposers meet their --- and --- requirements by
degrading --- organic matter or ---. These are also known as ---
energy and nutrient
dead
detritus
saprotrophs
88
Sapro means
to decompose
89
Decomposers secrete ---- that breakdown --- materials into simple, inorganic materials, which are subsequently ---
digestive enzymes
dead and waste
absorbed by them.
90
In an aquatic ecosystem, --- is the major --- for energy flow.
GFC
conduit
91
As against this, in a terrestrial ecosystem, a much larger fraction of energy flows through the ---- than ----.
detritus food chain than through the GFC
92
--- food chain may be connected with the grazing food chain at some levels
Detritus
93
some of the organisms of --- are --- to the GFC animals, and in a natural
ecosystem, some animals like ----, ---- etc., are omnivores.
DFC, prey
cockroaches, crows,
94
These ---- of food chains make it a food web. How
would you classify human beings!
natural interconnection
95
Organisms occupy a place in the ---- or in a
community according to their---- with other organisms.
natural surroundings
feeding relationship
96
Based on the -----, organisms occupy a specific place in the food chain that is known as their -----
source of their nutrition or food
trophic level.
97
---- belong to the first trophic level, herbivores (primary consumer) to the
second and carnivores (secondary consumer) to the third
Producers
98
1st trophic level/Producer (---) ex:
Plants
Grass, trees, phytoplankton
99
2nd trophic level/1' consumer (---) ex:
Herbivore
zooplankton grasshopper, cow
100
third trophic level / 2' consumer (---)
ex:
Carnivore
birds, fishes, wolf
101
4th trophic level / 3' consumer (---)
ex:
Top carnivores
Man, Lion
102
The important point to note is that the amount of energy --- at successive trophic levels.
decreases
103
When any organism ---it is converted to detritus or ---- that serves as ---- source for decomposers.
dies
dead biomass
an energy
104
Organisms at each trophic level depend on those at the ---- for their energy demands.
lower trophic level
105
Each trophic level has a certain ---- at a particular
time called as the --- crop.
mass of living material
standing
106
The ---- is measured as the ---- (biomass) or the number in a unit area.
standing crop
mass of living organisms
107
The biomass of a species is expressed in terms of --- or ----
fresh or dry weight.
108
Measurement of biomass in terms of --- is more accurate.
Why?
dry weight
109
The number of trophic levels in the ---- is restricted as the transfer of energy follows ---- law
grazing food chain
10 per cent
110
10% law:
only 10 per cent of the
--- is transferred to each trophic level from the ----.
energy
lower trophic level
111
In nature, it is possible to have so many ---– producer, herbivore, primary carnivore, secondary carnivore in the grazing food chain
Do you think there is any such limitation in a detritus food chain?
levels
112
The base of a ---- is broad and it narrows towards the --- . One gets a similar shape, whether you express the --- or ---- relationship between organisms at ---- levels.
pyramid, apex
food or energy
different trophic
113
This, relationship of orgs in diff trophic levels is expressed in terms of
---, --- or ----.
number, biomass or energy
114
The base of each pyramid represents the ---- trophic level while the apex represents -----.
producers or the first
tertiary or top level consumer
115
The three types of ---- that are usually studied are (a) pyramid of number; (b) pyramid of biomass and (c) pyramid of energy
ecological pyramids
116
Pyramid of numbers in a grassland ecosystem (---- pyramid)
Only ---top-carnivores are
supported in an ecosystem based on production of nearly ---- plants
upright
three, 6 millions
(based on figure given in ncert)
117
Pyramid of biomass (---- pyramid) shows a ---- in biomass at higher trophic levels
mostly this is of grassland ig
upright
sharp decrease
118
---- pyramid of biomass-small standing crop of ---supports large standing crop of ----
Inverted
phytoplankton
zooplankton
119
An ideal pyramid of energy, primary producers convert only ---- in the sunlight available to them into ---
1% of the energy
NPP
120
Any calculations of ---, ---- or ----, has to include ---- at that trophic level.
energy content, biomass or numbers
all organisms
121
No generalisations we make will be true if we take only a ---- at any trophic level into account.
few individuals
122
A given organism may occupy more than one trophic level SIMULTANEOUSLY.
T/F
True
123
One must remember that the trophic level represents a ----, not a ---as such.
functional level
species
124
A given species may occupy more
than one trophic level in the ---- and ----
for example,
a sparrow is a ---- when it eats seeds, fruits, peas, and a ---- when it eats insects and worms.
Can you work out
how many trophic levels human beings function at in a food chain?
same ecosystem at the same time;
primary consumer
secondary consumer
125
In -----, all the pyramids, of number, of energy and biomass are upright, i.e., ----- are more in number and biomass than the herbivores, and herbivores are more in number and biomass
than the carnivores.
most ecosystems
producers
126
Also ---- at a lower trophic level is ALWAYS more than at a --- level
energy
127
There are exceptions to this generalisation:
If you were to count the
number of ---- feeding on a ---, the small birds dependent on it and the larger birds eating the smaller
draw what shape you will get
insects, big tree
128
The pyramid of ---- in sea is generally ---- because the biomass of ---- far exceed -----
biomass
inverted
fishes far exceeds that of phytoplankton
129
Pyramid of --- is always upright, can never be inverted, because when energy flows from a particular trophic level to the next trophic level,
some energy is ---- at each step.
energy
always lost as heat
130
Each --- in the energy
pyramid indicates the amount of energy present at each trophic level in a
given ----- or ---- per ---
bar
time or annually per unit area.
131
However, there are certain limitations of ---- such as :
1. it does not take into account the same species belonging to ---- trophic levels.
2. It assumes a ----, something that almost
--- in nature
3. it does not accommodate a ---.
4. ---- are not given any place in ecological pyramids even though
they play a --- in the ecosystem.
ecological pyramids
two or more
simple food chain
never exists
food web
saprophytes
vital role
132
___ and____ are the 2 main structural features of ecosystem
Species composition and stratification
133
1' productivity is the rate of ---- or ------ of the producers
capture of solar energy
biomass production
134
rate of capture of solar energy or total production of organic matter is ----
GPP
135
NPP is the remaining biomass or energy left after -----
utilization of producers
136
Secondary productivity is the rate of ---- by the consumers.
assimilation of food energy
137
Decomposition involves ---- processes, namely fragmentation of
detritus, leaching and catabolism.
three
138
The ---- and ---- of ---- elements through the various components
of the ecosystem is called nutrient cycling;
nutrients are ---- through this process
storage and movement of nutrient elements
repeatedly used
139
Nutrient cycling is of two types—--- and -----
gaseous and sedimentary.
140
---- or ---- is the reservoir for the gaseous type of cycle (----), whereas ---- is the reservoir for sedimentary type (----)
Atmosphere or hydrosphere; carbon
Earth’s crust
phosphorus
141
Products of ecosystem processes are named as -----, e.g., purification of air and water by---.
ecosystem services
forests
142
