jueves, 6 de noviembre de 2014

Bioaccumulation and Biomagnification

BIOACCUMULATION

Is the accumulation of a chemical that breaks down slowly and it is concentraded in the organism. It can be hight enought to cause decrease or deat.



BIOMAGNIFICATION

Is the bioaccumulation of a substance in the food chain, cause by a transfer of residues of the substance in smaller organism that are food for larger organism in the chain.

Result in an organism having highter concentrations of a substance that is present in the organism`s food.


FOOD CHAIN AND FOOD WEB

Food chain:

  • It ilustrates how energy and nutrients move from one organism to another. 
  • Shows transfer of energy from one thropic level to another. 
  • Show how matter and energy move trought an ecosystem. 

Food web: 
  • Complex network of interconected food chains. 
There are: 
  • Grazing food web 
  • Betritial food web 



Key word_____ THROPIC LEVEL: Position that an organism occupies in a food chain.

Thropic levels:

  • Producers
  • Primary consumers
  • Secondary consumers 
  • Tertiary consumers
  • Quaternary consumers  

ECOLOGICAL RELATIONS

Simbiosis: Any of several living arragments between members of two different species, incluiding mutualism, commensalism and parasitism.  


  Parasitism: Relationship between individuals of two species in which one benefits at the expense of the other, sometimes without killing it. 



Mutualism: Assosiation between organisms of two different species in which each is benefited. 


Commensalism: Relation between individuals of two species : one species obtains food or other benefits from the other without ether harming or benefitingthe latter. 



Predation: One organism kills and consumes another. 



jueves, 25 de septiembre de 2014

Ecological Niche


  • Is how an organism makes a living
  • Every relationship that an organisms may have 
  • Behavior 
  • where it lives, how it responds to resources available predators,competitors

What is a system?

SYSTEM 
  Is an essamble of parts and the relationships between them, which together constitue a whole.

 System composition :

  • storages: matter and energy 
  • flows: inputs and outputs
  • processes: tranfer and transfromation 
  • feed back mechanisms: positive feedback and negative feedback
Types of systems: 
  • Open system: Exchanges both  energy and matter
  • Closed system: Exchanges energy but not matter
  • Isolated system: Neither matter or energy crosses


Digestive system is an open system. 




                                                            A fishbowl is a closed system

miércoles, 24 de septiembre de 2014

Biological Organization


  1. Atmosphere
  2. Hydrosphere
  3. Lithosphere
  4. Ecosphere
  5. Biosphere
  6. Ecosystem
  7. Community
  8. Population 
  9. Species
  10. Multicellular organisms
  11. Organism
  12. Organ System
  13. Organ
  14. Tissue
  15. Cell
  16. Organell
  17. Molecules 
  18. Atom 
  19. Subatomic particle 

Population


Are all the members of one species inhabiting the same area.


What is a Community ?



  • Is the interaction of two or more populations of different species living and interacting in the same area. 
  • Group of populations living and interacting with each other in a common habitat.
  • contains all the biotic components of a habitat. 





Ecosystem: Comes from the Grek word OIKOS which means home and system.
- A community together with its nonliving surroundings.
- Interaction of biotic and abiotic factors.



 Abiotic factors: Nonliving components.

There are two kinds of abiotic factors:

  1. Physical:  sunlight and shade, amount of precipitation, altitude and latitude, nature of soil and wind. 
  2. Chemical:  salinity of water, level of dissolved O2 and other gases, level of plant nutrients, pH of solid and water and level of natural and artifitial toxic substances.   


 Biotic factors: Living components in an ecosystem. 

  1. Autotrophs: photoautotrophic and chemoautotrophic. 
                Photoautotrophs: has clorophyll and carry on photosyntesis.
                Chemoatotrophs: bacteria that obtain energy from the oxidation of inorganic compounds. 


      2. Heterotrophs: 

  • Need a source of pre formed nutrients 
  • consume tissues of the other organisms
  • consumers are classified according to the type of food they eat  

Biosphere

What is Biosphere? 
 is that part of the Earth inhabilited by living organisms; includes both the living and nonliving components.