Biosphere-Origin ,Structure & Development

Presented by Alexander

10b

What is the Biosphere?

-The term biosphere was introduced by the Austrian geologist Zuk in 1875

-The biosphere is the total sum of all living organisms and parts of physical environment which are being changed by the vital activity of organisms. In other words the part of the Earth’s surface and atmosphere in which there are living organisms.

Functions of the organisms in the biosphere

4 main functions:

-transform energy

-maintain the gas content of the atmosphere constant

-obtain chemical elements from the physical environment

-break down organic matter into inorganic one

Functions of the organisms in the biosphere

-Energy transformation-green plants convert light energy into chemical energy that animals use. Thus chemical energy is distributed between all living organisms

-Maintaining the gas content-O2 is released in the process of photosynthesis and CO2- in the process of respiration.The constant quantity of O2 & CO2 in the atmosphere is a result of the vital activity of organisms.

Functions of the organisms in the biosphere

-Obtaining chemical elements-organisms obtain some chemical elements ,necessary for their construction ,from their physical env.

-Breaking down of organic matter-Decomposers transform organic compounds into inorganic ones and in this way plants can use them again.

Boundaries of the Biosphere

-Atmosphere boundary-the ozone layer(Spores of microorganisms can be encountered at a height of 22km)

-Hydrosphere boundary-living organisms are encountered even in the Marian trench

-Lithosphere boundary-A great number of bacteria are found in oil wells at a depth of 2km.Very few bacteria are found at a depth of 4km.

Biosphere development and evolution

The biosphere came into being when life began on Earth(~3,5 billion years ago). Since then the biosphere has constantly been changing as the species diversity has been increasing it has become more complex and it’s productivity has increased.

Biosphere development and evolution

The evolution of the biosphere has passed through three basic stages:-First stage-biochemical cycles originate and energy flows through them

-Second stage-life moves on land and the structure of the biosphere becomes more complex

-Third stage-the species of man originates and the techno sphere has comes into being.