“Explore major ecosystems such as forests, deserts, oceans, and wetlands, and understand their unique roles in supporting biodiversity and life on Earth.”
Biology Class 12 Chapter 12 Notes
The amount of energy left plants have met their respiratory needs is net eprimary production , which shows up as plant: Biomass
The earth surface covered with water is: 21%
Which of the following is NOT recycled in ecosystem: Energy
Water used for industrial purposes is about: 90%
In succesion lithoseres takes place on: Bare rocks
At the time of independence in 1947 the population of pakistan was: 32.5 m
Clearance of vast areas of forest for lumber planting subsistence crops or grazing cattle is called as: Deforestation
A natural process in which surface soil is removed by the action of water or wind is: Erosion
Oxone molecule is made up by binding of three atoms of: Oxygen
Each nuclear power station only can last for about: 30 years
As CFCs rise to the atmosphere ultraviolet rays release: Chlorine
The total energy from the sun is happened by the producers in an ecosystem is about: 10%
Which statement defines the net primary production in an ecosystem over a given time period: The total amount of organic matter in the plants in excess of that used in respiration
Rain that falls on high areas such as mountains possesses large amount of garvitational: Potential energy
The study of hman populations and things that affect them is called: Demography
The best way to increase food production from ecosystem view point is: Use of genetically improved varieties of seeds
Only 30% of the earth is dry land the remainder being covered with: Water
What would be expected to happen if all the nitrogen-fixing organisms ceased to exist: All organisms would die out
The decline in thickness of the ozone layer is caused by increasing level of: Chlorofluorocarbon
A form of air pollution in which airbone acids produced by electric utility plants and other sources fall to Earth in distant regions is: Acid rain
Modern man is called: Homo sapiens
In oceans especially in tropical regions temperature of surface water is about: 25oC
A change in the community structure of an ecosystem over a period of time is: Succession
A natural process in which surface soil is removed by the action of water or wind is: Erosion
At the time of independence in 1947 the population of pakistan was: 32.5 m
Rain that falls on high areas such as mountains possesses large amount of garvitational: Potential energy
Fresh water ecosystem covers less than: 1%
Which statement defines the net primary production in an ecosystem over a given time period: The total amount of organic matter in the plants in excess of that used in respiration
Each nuclear power station only can last for about: 30 years
Oxone molecule is made up by binding of three atoms of: Oxygen
The producers in limnetic zone are: Cyanobacteria
Important : Review all previous years’ 12 class past papers for comprehensive practice and better exam preparation.