DIGITAL LIBRARY OF GLT SARASWATI BAL MANDIR, NEHRU NAGAR.

1. Environmental is very
important political and
social movement with goal
to protect nature
environment by
emphasizing importance of
nature role in protection
of the environment in
combination with various

2.  Complete ecological units thaThe natural environment encompasses
all living and non-living things occurring naturally earth or some region
thereof. It is an environment that encompasses the interaction of all
living species.[1] The concept of the natural environment can be
distinguished by components:
 t function as natural ystems without massive human intervention, including
all , and that occur within their boundaries.
 Universal andlack clear-cut boundaries, such as and as well as and not
originating from human activity.
 The natural environment is contrasted with the , which comprises the
areas and components that are strongly influenced by humans. A
geographical area is regarded as a natural environment.
 It is difficult to find absolutely natural environments, and it is common
that the naturalness varies in a continuum, from ideally 100% natural in
one extreme to 0% natural in the other. More precisely, we can consider
the different aspects or components of an environment, and see that

3. The vital processes carried out by
living organisms in order to
maintain and sustain life.Various
functions are going inside our body
and inside the body of all living
organisms must go on even when
they are not doing anything
particular.

4.  Living things react to stimuli.
 Living things interact with
their environment which includes
members of the same and
other species.
 Living things have a metabolism:
they take infood which they
convert to the energy they need.
 Living things reproduce : they give
birth to others of the same
species. This is not true of

5. An ecosystem is a of living organisms
(plants, animals and microbes) in
conjunction with the of their
environment (things like air, water and
mineral soil), interacting as a
systemThese biotic and abiotic
components are regarded as linked
together through nutrient cycles and
energy flowsAs ecosystems are
defined by the network of interactions
among organisms, and between

6. The sequence of the transfer of food energy
from one organism to another in an ecological
community. A food chain begins with
a producer, usually a green plant or alga that
creates its own food through photosynthesis.
In the typical predatory food chain, producers
are eaten by primary consumers(herbivores)
which are eaten by secondary
consumers (carnivores), some of which may in
turn be eaten by tertiary consumers (the top
carnivore in the chain).
♦ Many species of animals in an ecological

8.  The green plants in a terrestrial ecosystem
capture about 1% of the energy of sunlight
that falls on their leaves and convert it into
food energy.
 When green plants are eaten by primary
consumers ,a great deal of energy is lost as
heat to the environment ,some amount goes
into digestion and in doing work and the rest
goes towards growth and reproduction .An
average of 10% of the food eaten is turned
into its own body and made available for the

9.  Level 1: Plants and algae make their
own food and are called primary
producers.
 Level 2: Herbivores eat plants and are
called primary consumers.
 Level 3: Carnivores which eat
herbivores are called secondary
consumers.
 Level 4: Carnivores which eat other
carnivores are called tertiary
consumers.

10. The trophic level of an organism is the
position it occupies in a food chain. The
word trophic derives from
the Greek τροφή (trophē) referring to
food or feeding. A food chain represents
a succession of organisms that eat
another organism and are, in turn, eaten
themselves. The number of steps an
organism is from the start of the chain is
a measure of its trophic level. Food

11. Rabbits eat
plants at the
first trophic
level, so they

12. Foxes eat
rabbits at the
second trophic
level, so they

13. Golden
Eagles eat
foxes at the
third trophic

14. The fungi on this
tree feed on
dead matter,
converting it

15. Food webs largely define ecosystems, and the
trophic levels define the position of organisms
within the webs. But these trophic levels are
not always simple integers, because organisms
often feed at more than one trophic level.[For
example, some carnivores also eat plants, and
some plants are carnivores. A large carnivore
may eat both smaller carnivores and herbivores;
the bobcat eats rabbits, but the mountain lion
eats both bobcats and rabbits. Animals can also
eat each other;the bull frog eats cray fish and
crayfish eat young bullfrogs. The feeding
habits of a juvenile animal, and consequently its
trophic level, can change as it grows up.
The fisheries scientist Daniel Paul sets the values

16. It was once believed that fish at higher trophic levels
usually have a higher economic value; resulting
in overfishing at the higher trophic levels. Earlier
reports found precipitous declines in mean trophic
level of fisheries catch, in a process known
as fishing down the food web However, more recent
work finds no relation between economic value and
trophic level;[12] and that mean trophic levels in
catches, surveys and stock assessments have not in
fact declined, suggesting that fishing down the food
web is not a global phenomenon.[13] However Pauly et
al. note that trophic levels peaked at 3.4 in 1970 in
the northwest and west-central Atlantic, followed
by a subsequent decline to 2.9 in 1994. They report
a shift away from long-lived, piscivorous, high-
trophic-level bottom fishes, such as cod and

18. A food web (or food cycle) depicts feeding connections (what-eats-what)
in an ecological notes and hence is also referred to acosumex
resources system.Ecologists can broadly lump all life
formsthe heterotrophsTo into one of two categories called trophic
levels: 1) the autotrophs and 2) maintain their bodies, grow, develop,
and to reproduce, autotrophs produce organic matter from inorganic
substances, including both minerals and gases such as carbon-di-oxide.
These chemical reactions require energy which mainly comes from
the sun and largely by photosynthesis although a very small amount
comes from hydrothermal vents and hot-springs. A gradient exists
between trophic levels running from complete autotrophs that obtain
their sole source of carbon from the atmosphere, to (that are
autotrophic organisms that partially obtain organic matter from
sources other than the atmosphere, and hat must feed to obtain
organic matter. The linkages in a food web illustrate the feeding
pathways, such as where heterotrophs obtain organic matter by
feeding on autotrophs and other heterotrophs. The food web is a
simplified illustration of the various methods of feeding that links an
ecosystem into a unified system of exchange. There are different