– study of relationship between organisms and
– functional unit of nature encompassing interaction
between its biotic and abiotic components.
– surrounding where organisms live. It has abiotic
components like rocks, soil, air, water and light. It also
has biotic components like plants, micro organisms,
animals. 70% of all species are animals [out of 10 animals
7 are insects] and 22% are plants.
chain - a series of organisms feeding on each other
taking part at various biotic levels. Each step of the
food chain is called trophic level. At each
trophic level, 10% of the energy present is passed on to
the higher trophic level. [10% law] i.e. from
plants to herbivores to carnivores.
of energy in trophic levels is unidirectional. The pyramid
of trophic levels shows sharp decline from bottom to top.
organisms are classified into 5 broad kingdoms: Monera,
Protista, fungi, plantae, and animalia.
Fig 1: Biomass Pyramid
the aquatic biomass pyramid is inverted. A small mass of
phytoplankton support a large mass of zooplanktons.
at each level organisms are eaten by several other
organisms at higher level, we use food webs to
is phenomenon when harmful substances absorbed by lower
level are passed on to higher trophic levels. However at
higher trophic levels, the concentration of these
substances increases [magnifies] as these feed on large
number of organisms from lower trophic levels.
is the natural aging of the river or water body
due to nutrient enrichment. Acceleration of this happens
when manmade activities release pollutants in the lakes.
This affects aquatic life and increases growth of water
hyacinth [most problematic weed]. The lake literally
chokes to death.
fortification is breeding crops with higher levels
of vitamins and minerals.
remediation is use of microbes to make toxic waste
Mega biodiversity regions
biodiversity region is the region between tropic of cancer
and Capricorn. This is since the tropical areas have been
undisturbed for a long time enough for species
diversification also more solar energy is available and
temperature is constant and predictable. Half the world’s
biodiversity is located in few countries like Brazil,
India, Columbia, equator, Peru, Indonesia, Zaire,
Madagascar, China and Malaysia.
Small but rapid changes taking place in a single organism
to overcome changes in thesurrounding. When we reach high
altitudes, due to low pressure body doesn’t get enough
oxygen and this is countered by increasing breathing rate,
RBC count inblood and reducing binding affinity of
when we move from plains to mountains we breathe faster.
have long legs to keep body away from the heat of the
ground. They don’t sweat, their dung is dry and urine is
have streamlined body and fins to help move and
change direction in water. They have scales on skin to
protect the body and help in easy movement. Gills help
them use oxygen dissolved in water.
animals use the carbonates dissolved in sea water
to make their shells. This is another reason why CO2 is
less in the atmosphere.
oxygen dissolved in water is less, aquatic animals breathe
faster than terrestrial. However as temperature decreases
oxygen solubility in water increases, thus aquatic animals
are more comfortable in cold waters than warm.
divers have a lower concentration of nitrogen and
higher conc. of oxygen and helium in the breathing tank as
under pressure of sea the other atmospheric gases dissolve
more in blood. When the diver comes to shore, this
pressure decreases and dissolved gases are released. This
would create bubbles in blood vessels.
bears have two thick fur layers under their skin and
a layer of fat that insulates them from cold.
animals are rarely found in cold areas as they might lose
body heat quickly due to the larger surface area relative
to the volume.
deep oceans we find brown algae as only certain
components of visible light can penetrate depth of sea.
plants like cactus don’t have leaves but spines. They loose
very little water by transpiration. Photosynthesis is
carried out in the stems. CAM pathway is a special
photosynthesis mechanism which keeps stomata closed during
it. They have very long roots.
plants might have cone shaped structure with sloping
branches or needle like leaves. The rainwater or snow
slides off easily. Animals in such areas have thick skins
birds, fish even insects migrate seasonally to
more hospitable regions.
in tropical rainforests see intense competition
lack nervous system or muscles.
smog is formed due to peroxyacetyl nitrate,
hydrocarbons, ozone, nitric oxide, formaldehyde and
sunlight. It is called oxidizing smog. To solve this we
could plant pinus, junipirus, and pyrus as they
increase CO2 solubility in soft drinks, the bottle is sealed
under high pressure.
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