The document defines ecology and describes various ecological concepts and components. Ecology is defined as the scientific study of the interactions between organisms and their physical environment. It discusses the components of different ecosystems including producers, consumers, decomposers and their interactions through food chains, food webs and nutrient cycles. Major ecosystem types described are forests, grasslands, deserts, freshwater and marine systems.

2.  The meaning of word ecology was given by Hackle
in1869.
 Its derived from two Greek words ‘Oikos’means house,
habitat and ‘Logos’means to study.
 Definitions:
(1)The Scientific study of the interactions of the
organisms with their physical environment and with
each other is called ecology. (Helena
Curtis,1975)
(2)The study of relations between organisms and totality
of the biological and physical factors affecting them or
influenced by them. (R.L Smith, 1977)

3. (1)Based on study area: (a) Autecology
(b) Synecology
(2)Based on Environment or Habitat:
(a) Aquatic Ecology study of interaction of
organisms in Water.
(b) Terrestrial Ecology study of interaction of
organisms on Land.
(3)Based on Taxonomy :
(a) Plant Ecology
(b) Animal Ecology

4.  “The system resulting from the interaction of all
the living and non living factors of the
Environment.”
 It may be defined as “Natural function Ecological
unit comprising of living organisms and their non
living environment that interact to form a stable
self-supporting system. It may also be defined as
self-regulating group of biotic communities of
species interacting with one another and with
nonliving environment exchanging energy and
nutrient.

6. (1) Natural Ecosystem :
(i) Terrestrial Ecosystem : Forest, Grassland,
desert etc.
(ii) Aquatic ecosystem :
(a) Fresh Water which may be Lotic (Running
water) or Lentic (standing water).
(b) Marine water such as deep bodies as
ocean or shallow ones as Sea or an estuary.
(2) Artificial (Man Engineered) Ecosystem :

8. (1) Biotic/Living Components:
(a)Producers/ The Autotrophs: Plants, trees.
(b)Consumers:
(i) Macro consumers→ eating living tissues
1.Herbivores/Primary consumers: Rabbit, cow, deer etc.
2.Carnivores/Animal Eaters: Lion, Tiger, Leopard etc.
3.Omnivores/Plant and Animal Eaters: Humans, Rat,
Fox and many birds.
(ii) Micro Consumers → eating dead tissues
1.Detritivores/ Saprotrophs : Ants, termites, crabs etc.
2.Reducers/Decomposers/Transformers: Bacteria,
Fungi prozoa and other microbes.

10. (1) Tropic structure
(2) Food chain
(3) Food Web
(4) Biogeochemical Cycles
(5) Energy Flow
(6) Ecological Pyramids.

12.  (i) Grazing food chain :

13.  (ii) Detritus food chain :

15.  Food chain
(1) The sequence of eating
and being eaten in an
ecosystem by different
organisms is termed as
food chain.
(2) It is simple in nature.
(3) Linear food chain can not
give balanced and stable
Ecosystem.
(4) No choice of taste or food
is available to any
organisms in linear food
chain.
 Food web
(1) The complex network of
various food chain where
organisms are connected at
different trophic levels are
termed as food web.
(2) It is more complex in nature.
(3) Complex food webs are very
essential for ecosystem
Balance and Stability.
(4) Food webs operate according
to the taste and food
preference of the organisms at
each trophic level.

16. ▶ Hydrological or Water Cycle
▶ Gaseous Cycle
1.Carbon cycle
2.Nitrogen cycle
3.Sulphur cycle
4.Oxygen cycle
▶ Sedimentary Cycle

18. (1) To cater more water demand for domestic and industrial
purposes we withdraw more amount of fresh water from
river, pond, lake and underground sources, and depleting
the available water resources.
(2) Addition of industrial and domestic waste water to river
and stream pollute the fresh water source.
(3) Reduction in vegetative cover may increase surface runoff
and reduces percolation of water and which results in
depletion of ground water table.
(4) Global warming may alter hydrological cycle.
(5) Heavy deforestation reduces the transpiration loss of
water through plants and trees.

23. ▶ Forest Ecosystem
1.Tropical Rain Forests
2.Tropical Deciduous Forests
3.Tropical shrub Forests
4.Temperate Rain Forests
5.Temperate Deciduous Forests
6.Evergreen coniferous Forests
▶ Grassland Ecosystem
▶ Desert Ecosystem
▶ Aquatic Ecosystem

24.  Components
(1) Abiotic :These are the inorganic as well as
organic substances presents in soil and
atmosphere.
(2) Biotic :
1. Producers: Trees, Plants, etc.
2. Consumers:
(a) Primary consumers: Ants, flies, bugs, spiders,
leaf hoppers etc.
(b) Secondary consumers: Snakes, birds, lizards,
fox etc.
(c) Tertiary consumers: Lions, Tigers, etc.
3. Decomposers: Fungi, bacteria etc.

25.  Components
(1) Abiotic :These are the Nutrient present in soil
and atmosphere.
(2) Biotic :
1. Producers: Mainly grasses and few shrubs.
2. Consumers:
(a) Primary consumers: Cows, buffaloes, deer,
sheep, rabbit, etc.
(b) Secondary consumers: Snakes, birds, lizards,
fox etc.
3. Decomposers: Fungi, bacteria etc.

26.  Components
(1) Abiotic :These are the Nutrient present in
soil and atmosphere.
(2) Biotic :
1. Producers: Mainly shrubs, bushes, some
grasses and few trees.
2. Consumers: Reptiles, insects, rodents, birds
mammals and camels.
3. 3. Decomposers: Fungi, bacteria etc.

27.  The major Aquatic ecosystem are:
(1) Pond Ecosystem
(2) Lake Ecosystem
(3) Stream and Riverine Ecosystem
(4) Marine Ecosystem
(5) Estuarine Ecosystem

28.  It is defined as any body of water over 1 km²
that is inundated wet for more than 8
months.
 It is small fresh water stagnant ecosystem.
 They are shallow water bodies which play
important role in the villages.
 They contain various types of aquatic plant,
fishes, birds, and algae.
 Due to human activities and over uses of
pond water they get polluted.

30.  A lake is a body of water completely
surrounded by land.
 They may be salty or fresh.
 Lakes are short lived surface features because
the water can sink into the ground or
evaporate into the sky.
 For a lake to remain, it must be fed by river
or rainfall.

31. (1) Abiotic Components: Light, heat, pH, water,
CO₂, Oxygen, calcium, etc.
(2) Biotic Components:
1. Producers: autotrophic rooted green plants
partly or fully submerged, phytoplaktons.
2. Consumers:
(a) Primary Consumers: Benthos, Zooplanktons,
Neustons, Periphytons.
(b) Secondary Consumers: Small fishes.
(c) Tertiary Consumers: Some large fishes.
3. Decomposers: Fungi, bacteria and
actinomycetes.

32.  Components:
(1) Abiotic components: Solar radiation, pH,
organic and inorganic compounds,
dissolved oxygen etc.
(2) Biotic Components:
(a) Producers: Green algae.
(b) Consumers: water sponges, larvae, snails,
flat worms, fish etc.
(c) Decomposers: Various bacteria and fungi.

33.  Components:
(1) Abiotic Components: Salt, sodium, sulphur etc.
(2) Biotic Components:
(a) Producers: Phytoplanktons, microscopic algae,
sea weeds etc.
(b) Consumers:
1. Primary Consumers: Crustaceans, fish etc.
2. Secondary Consumers: fish, herring, shad, etc.
3. Tertiary Consumers: cod, haddock etc.
(c) Decomposers: bacteria, fungi.

34.  An Estuarine is semi closed coastal body of water
that has 3 connection with sea.
 This is where river fresh water and salty sea
water meets.
 Estuarine are most fertile place of the world.
 Components:
(1) Producers: sea weeds, sea grass, marsh grass,
benthic microphytes, phytoplanktons etc.
(2) Consumers: zooplanktons, crabs, crustaceans,
fishes etc.
(3) Decomposers: Bacteria and Fungi.