jueves, 5 de febrero de 2015



 1)   ECOSYSTEMS


Ecosystem is made up of a community of living things in a physical environment
The biosphere is the conjunct of all the ecosystems of the Earth.
Kinds of ecosystems. There are two big groups of  physical environment in ecosystems:
- Terrestrial: forest, grasslands, desert, tundra….
- Aquatic: fresh water and marine

2)    LIVING THINGS IN AN ECOSYSTEM

 All living things in an Ecosystem are grouped into
Species: It is a group of living things with the same characteristics. Ex: lions
Population: It is all the members of one species living in the same ecosystem
Community: It is made up of all  the populations that interact in an ecosystem. Ex: tigers, lions, giraffes, zebras, etc.
Habitat: it is the place within an ecosystem where a population lives.



3) FACTORS THAT INFLUENCE LIVING THINGS IN A PHYSICAL ENVIRONMENT OF AN ECOSYSTEM

1.- Terrestrial ecosystem:
 -  Type of Climate:  it depends of  temperature, humidity and seasons we are
  -  Soil conditions
  -  Terrain
2.- Aquatic ecosystem
- Salinity (the amount of salt in the water)
            + Freshwater ecosystem: Low levels of salt
            + Marine ecosystem: higher levels of salt
- The amount of light. It depends on the depth and clarity of water (plants and algae need light to grow)
- The water current
- The temperature of water
- Type of seabed and riverbed

4)   RELATIONSHIPS BETWEEN PHYSICAL ENVIRONMENT AND LIVING THINGS

The physical environment affects the type of vegetation in an ecosystem. (combination of climate, soil and terrain)
The type of vegetation determines the type of animals that live in an ecosystem. Ex: birds cannot built their nests in grasslands
Living things can modify the environment. Ex : moles modify the terrain digging   burrows in the ground.

5)    RELATIONSHIPS BETWEEN LIVING THINGS

 In ecosystems, living things interact with each other in many ways:
There are three types of relationships :
- Food Chain: Certain species eat other species. Ex deer is eaten by lions
- Competition: Species have the same needs and compete for them.
   Ex: Zebras and giraffes  eat grass of the same terrain.
- Cooperation: Species interact and obtain a mutual benefit . Ex:  shark and fish      that cleans shark body.


A) Food Chain/ Food relationships/ nutrition


In an ecosystem there are two main food relationships :
- Producers: They produce their own food  from sunlight, water and mineral salts obtained from the soil . They can be Terrestrial (plants) and Aquatic (algae).
- Consumers: They eat other living things.

Kinds of Consumers

- Primary consumers: they get  energy from producers . Ex : Buffalo.
- Secundary consumers: They get energy eating hervivores.. (Carnivores). Ex: tiger.
- Tertiary consumers: they are carnivores that eat other carnivores
Ex: human beings, eagles.
- Other Consumers.
            + Predators: hunt other animal for food. Ex: Tigers
            + Scavengers: eat the dead bodies. Ex: Vultures
            + Parasites: They feed off of other living things without                      killing them.Ex: mosquitoes.
     +Descomposers: they are bacteria and fungi that                        descompose the remains  of living things.

6.- FOOD CHAINS AND FOOD WEBS


Food chain: It shows how  Species are  connected to   one another  by  food relationships. 
There are many different food chains  in an ecosystem . 
One species can appear in various food chains.

Food webs : They show how plants and animals are interconnected. They are a combination of various food chains.


jueves, 22 de enero de 2015