1. Environmental Studies
PLEASE NOTE THAT I HAVE SIFTED THROUGH THE IEB FINAL PAPERS
FROM 2011 TO 2018 AND ADDED SOME INFORMATION THAT KEPT
COMING UP. THIS INFORMATION IS IN PINK. I HAVE ALSO CHECKED
THROUGH THE SAGS DOCUMENT TO MAKE SURE THAT ALL THE
RELEVANT INFORMATION IS HERE. J
1. Population Ecology
1. Ecology: study of interactions of organisms with their physical and
biological environments
2. Population ecology: concerned with fluctuations in both size of a
population and factors that regulates these fluctuations
3. Biosphere: part of earth where living organisms are found
4. Ecosystem: made up of groups of different species or organisms that
interact with each other and the environment [NEED TO KNOW DEF.]
5. Organism: individual form of life composed of a single cell or a
complex of cells that are capable of growing and reproducing
6. Community: group of different species that inhabit and interact in a
particular area / flora and fauna in an ecosystem [NEED TO KNOW
DEF.]
7. Species: group of closely related organisms that are very similar to
each other and are usually capable of interbreeding and producing
fertile offspring
8. Individual: single organism capable of independent existence [NEED
TO KNOW DEF.]
9. Population: group of organisms of the same species that occupy the
same area and can breed freely with each other [NEED TO KNOW
DEF.]
10. Population size: total number of individuals in a population
11. Population density: Number of organisms per cubic metre
Individual > Species > Population > Community > Ecosystem > Biosphere
What affects the size of a population?
Increases Decreases
Natality (birth rate in animals or the Mortality (death rate)
production of seeds in plants)
SAHETI School, 2019