ESE Flashcards
is the study of nature and the facts about environment.
Environmental science
cannot be solved by mere laws. Public
participation is an important aspect which serves the environmental prtection.
Environmental Pollution or problems
due to various environmental hazards is an important
topic for environmental engineers to recognise and understand in order to protect
human society and ecosystems from harms or damages at local, regional or global
scales.
Environmental risk
is a threat to life, health, property, or ecosystems, i.e., it involves
something that could potentially be harmful.
hazard
Combustion of Fossil fuels, industrial effluence, pesticides
heavy metals.
Chemical hazards
Radioactive and UV radiations, Global warming, Chlorofluro
carbons, Noise etc.
Physical hazards
Bacteria, Viruses, Parasites.
Biological hazards
Living organisms cannot be isolated from their non-living environment because the later provides materials and energy for the survival of the farmer. True or False?
True
is therefore defined as a natural functional ecological unit comprising of living organisms and their non-living environment that interact to
form a stable self supporting system.
ecosystem
defined as the capacity to do work.
Energy
For living organisms, it is the basic forceresponsible for
running all the metabolic activities. The flow of energy from producer level totop consumer level is called
energy flow.
The flow of energy in an ecosystem
unidirectional. It flows from producer level to consumer level and never in the reverse direction.
The main source of energy in the ecosystem is
sunlight
Because, sun is the first step in the production of energy for living things, it is called
“Primary
production”.
Chemical reaction where green plants use water & carbon dioxide to store the
sun’s energy in glucose.
Photosynthesis
is stored in glucose.
ENERGY
is stored as starch in plants.
Glucose
The energy contained within producers and consumers is ultimately passed to the
decomposers
Only About 2% of energy from the sun is used by green plants & rest remains
unutilized. True or False?
False, 1%
Plants by photosynthesis convert solar energy into
protoplasm.
“the transfer of energy and nutrients through a series of organisms with repeated process of eating and being eaten”.
Food chain
The food relationship between various organisms is being depicted by linking all the
possible prey and predators of different food level. In an ecosystem linking of feeding
habit relations will provide
a food web
is a graphical representation that shows the relative amounts of energy or matter contained within each tropic level in a food chain or food web.
”Ecological pyramid”
shows the relationship between consumers and producers at different tropic levels in an
ecosystem.
”Ecological pyramid”
Types of ecological
pyramids:
a) pyramid of numbers
b) pyramid of biomass
c) pyramid of energy
Shows the relative number of individual organisms at each tropic level.
PYRAMID OF NUMBERS
represents the total dry mass (in grams per square meter of area) of all the
organisms in each tropic level at a particular time.
PYRAMID OF BIOMASS
represents the rate of energy flow and/or productivity at successive tropic levels. The
pyramids of energy are always upright.
PYRAMID OF ENERGY
is crucial for all organisms.
Nitrogen
Read the following: always press 1 until you understand it properly.
1) Nitrogen Fixation Conversion of N2 → NH3 Combustion, volcanic action, Lightning, Industrial processes (making fertilizer). Bacteria (Azotobactor, Clostridium, Nostoc etc.)
2) Nitrification Conversion of NH3 → NO3 Soil bacteria convert in a two step process.
3) Assimilation Roots absorb NH3, NH4, or NO3 and incorporate them into nucleic acids and
protein.
4) Ammonification Amino acids and nucleotides are broken down into waste products NH3 or
NH4
5) Denitrification The reduction of NO3 to N2 .Denitrifying bacteria return some of the nitrogen
to the atmosphere
is the circulation of oxygen in various forms through nature free in the air and dissolved in
water.
Oxygen cycle
second only to nitrogen in abundance among uncombined elements in the atmosphere.
Oxygen
are the main oxygen generators of the biosphere;
water
enters plants, etc., as CO2 o Bacteria process carbon in a fashion that allows it to be recycled. o Obtain
energy from the molecules, and convert carbohydrates to carbon dioxide as a result of respiration.
Carbon
The only cycle that does not have a gaseous state.
PHOSPHOROUS CYCLE
Read the following: always press 1 until you understand it properly.
The only cycle that does not have a gaseous state.
Inorganic phosphate PO 3- is released from rocks and sediments through the action of erosion.
Soil PO4 3- is absorbed by plants and incorporated into nucleic acids, phospholipids and ATP.
Animals obtain most of their PO4 3- by consumption of other animals and from water.
PO4 3- is released to the soil again by decomposers.
o Dissolved PO4 3- gets absorbed by algae and aquatic plants.
o Decomposers break down waste and returns PO4 3- to sediments on the seabed.
o Some returns to terrestrial environment through geologic processes and via seabirds.
is defined as, “A change in the community in which new populations of organisms gradually replace existing ones”.
Ecological succession
Occurs where there is no soil, e.g. after a volcanic eruption or a glacial retreat.
Primary Succession:
Community development in the areas that were previously occupied by another
community.
Secondary Succession: