IB Biology; Unit Four Ecology

Species

A group of organism with similar characteristics which can potentially produce offspring

\

Population

A group of organisms of the same species, who live in the same area at the same time

Why do species differentiate?

* Evolution requires genetic change, genetic change is driven by need
* One species can turn into two different species if they are separated by environment. Isolation will divide a species

What are the two main forms of nutrion?

Autotrophic (photosenthisis) and Heterotroph Nutrition

Autotrophic Nutrition

* This nutrition is received by absorbing carbon dioxide, water , and inorganic nutrients.
* An external source of light is needed to do this(plants are autotrophic)
* Convert carbon dioxide into carbon compounds

Heterotroph Nutrition

* these organisms can’t make carbon compounds and instead obtain energy from consuming other organisms

Saprotphs

*  obtain nutrients from dead organisms through external digestion.
* They secrete digestive enzymes into materials. Proteins, cellulose, and other carbon compounds are digested externally, and then absorb the sustenance that they require(these are mostly bacteria or fungi)
* Heterotroph

Consumer

* obtain nutrients from feeding on living organisms by ingestion. This means that they eat other organisms.
* Carnivores, omnivores, and herbivores

Detrivores

* obtain nutrients from detritus by internal digestion. They eat previously deceased organisms such as dead roots and leaves or decomposing animals.
* Detritivores eat non-living matter(usually worms and beetles)

Community

A group of different species living together and interacting with each other in an area. 

* Communities can work together through symbiotic and parasitic relationships, mentalism. This has no mention of the environment

Abiotic environment

the non-living surroundings of a community. Ecosystems are formed by interactions with this environment. Particularly the transfer of chemical elements between populations and the abiotic environment.

* Ecosystems look at all biotic (living) and abiotic (nonliving) factors

What is essential for a mesocosm?

* Autographs are an essential part of mesocosms, they produce carbon compounds and regenerate oxygen used in cell respiration.
* Saprotrophs Are also essential to decompose dead organic matter and recycle nutrients.
* Consumers and detritivores are not always essential, but are a regular part of an ecosystem, so they are often included.

Where does all energy in the food chain come from?

Light

Why is energy lost?

* The further up the food chain you go, the less nutrients there is to consume. This is because as the food chain goes on, more energy is lost. This is due to the fact that some animals die before they are eaten and some parts of an organism simply aren't eaten.

What eat dead organims?

Detritivors and saprotrophs

What are the trophic levels?

* producer, primary consumer, secondary consumer, and tertiary consumer are considered trophic levels

What are energy pyramids?

* These are diagrams that show how much energy flows through each trophic level.
* The amounts are shown per square meter of an area occupied by the community per year. 
* Energy may be lost through the levels, but biomass is also lost so the energy content per gram of the tissues of each level is not lower.

How is methane produced?

* This is produced naturally by a group of prokaryotes called methanogenic archaeans. They break down organic matter in anaerobic conditions and release methane as a waste product. The methane is then converted into carbon dioxide

How is carbon dioxide produced?

* Carbon dioxide is produced by the combustion of carbon compounds. It occurs naturally.

 **carbon sequestration**

* The process of taking carbon out of the environment and ‘locking it up’ in a substance for an extended period of time, and when it happens naturally it is called biosequestration

Peat and coal

* saprotrophs can’t break down dead organic matter in acidic and anaerobic conditions. This can be seen in bogs and swamps, so partially decomposed matter accumulates into peat. When peat is crushed overtime it forms coal.

How do greenhouse gasses work?

* The impact of a gas depends on its ability to absorb long-wave radiation as well as on the surface of the atmosphere.
* Greenhouse gasses trap radiation within the troposphere, raising temperatures because the now the short wave radiation can’t be released .

Atmospheric carbon dioxide

created by methane and natural gasses, respiration, decomposition, diffusion

What is a sink?

where carbon is stored over long periods of time like in natural gas and coal deposits. It can also be stored in plans as well

What is the greenhouse effect?

* 75% of the sun’s solar radiation reaches the earth, where most of it is absorbed and turned into heat, the earth then remits this as heat which is a longer wavelength. Between 70 and 85% of this heat is released into the atmosphere, which then warms up the earth because the accumulation of greenhouse gasses absorbs or reflects this long wavelength of energy.

What are examples of fluxes?

* This can occur from forest fires combustion, cell respiration and the burning of fossil fuels, or even by volcanoes.

What are examples of sinks in the carbon cycle?

* Sinks are methods of carbon storage in the ecosystem. These could be carbon compounds contained in plants, the oceans, and natural deposits of fossil fuels that have yet to be extracted. 
* Limestone is also classified as a sink in the carbon cycle. This carbon is from dead sea creatures that have formed into the limestone. If acid rain comes into contact with limestone, this carbon is released.