Beyond the EU: DORA and NIS 2 Directive's Global Impact
Science ppt by ankit
1.
2. a) Foodchain:-
A foodchainis the flowof foodenergyfromone organismto the next and to the next and so on. Theyusuallystartwith a
producer(plants) and end with a carnivore.In a foodchainan organismgetsfoodfromone groupof organisms.
eatenby eatenby
Eg:- Grass Deer Lion
(producer) (primaryconsumer) (secondaryconsumer)
eatenby eatenby eatenby
Grass Insects Frog Snake
(producer) (primaryconsumer) (secondaryconsumer) (tertiaryconsumer)
eatenby eatenby eatenby eatenby
Grass Moth Frog Snake Hawk
(producer) (primaryconsumer) (secondaryconsumer) (tertiaryconsumer) (quarternaryconsumer)
4. b) Food web :-
Foodwebisa groupof severalinterconnectedfoodchains.In a foodwebanorganismgetsfoodfrommorethan
onegroupof organisms.
5. 4) Trophic levels :-
Eachstepin a foodchain wheretransfer of foodenergytakesplaceis calledtrophiclevel.
The firsttrophiclevelconsistsof producers.
The secondtrophiclevelconsistsof primaryconsumers.
The thirdtrophiclevelconsistsof secondaryconsumers.
The fourthtrophiclevelconsistsof tertiaryconsumers.
Since thetransfer of foodenergydecreasesat everytrophiclevel,the numberof trophiclevelsare limitedand do not exceed
fouror five.
6. Energy flow in trophic levels :-
Green plants (producers) absorb about 1% of solar energy falling on
the leaves and stores it as food energy during photosynthesis.
During the transfer of food energy from one trophic level to the
next, 90% of the energy is lost to the environment and only 10% is
transferred to the next trophic level. So there is a decrease in the
amount of food energy transferred at every trophic level by 10%.
This is known as the 10% law.
7. Biological magnification (Biomagnification) :-
Harmful chemicals like insecticides and pesticides which are used to protect
crops from insects and pests are absorbed by plants and enter the food chain.
Since these chemicals are non biodegradable, they get accumulated at every
trophic level and their concentration increases. Since human beings occupy the
highest trophic level, the concentration of these harmful chemicals is maximum in
our bodies.
The increase in concentration of harmful chemicals in the bodies of organisms at
higher trophic levels is called biological magnification.
8. Human activities affect the environment :-
a) Depletion of ozone layer in the atmosphere :-
Ozone molecule contains three oxygen atoms (O3). At higher levels in the
atmosphere the UV radiation splits some oxygen molecules (O2) into free oxygen
atoms which combines with oxygen molecules (O2) to form ozone. It is highly
poisonous.
UV radiation
O2 O + O
O2 + O O3
The ozone layer present in the higher layer of the atmosphere protects the
earth from the harmful UV radiation from the sun. UV radiation causes skin cancer
in humans.
The ozone layer is being damaged by the use of chemicals like chloro fluoro
carbons (CFCs) used in refrigerators and fire extinguishers. So the use of CFCs is
now being reduced to protect the ozone layer.
9.
10. b) Managing the garbage we produce
The household waste is called garbage. Some of the garbage is
biodegradable and some are non biodegradable. Garbage causes
pollution of air, water and soil. So it should be disposed properly.
Some of the methods of garbage disposal are :-
i) Land fills
ii) Recycling
iii) Production of biogas and manure
iv) Preparation of compost
v) Incineration
vi) Sewage treatment
