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Flashcards in Ecology Deck (25)
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Define population

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


Define autotroph

Organism which produces carbon compounds for consumption


Define heterotroph

Organism which consume carbon compounds by eating other organisms


Define detritivore

Organism which obtains organic nutrients by internal digestion of waste products


Define saprotroph

Plant which obtains nutrients from dead organic matter by external digestion


Define community

Interacting populations occupying a given area, upon which they depend on its abiotic environment


What does an ecosystem include

-abiotic environment
-a community
-interactions in communities and between organisms and abiotic environment


What do ecosystems need to be sustainable?

-A nutrient cycle to maintain the supply of inorganic matter for organisms to survive
-Detoxification of waste products
-Energy availability


What is the main source of energy for most living organisms?

The sun.


Define food chain.

A sequence of organisms, each of which feeds on the previous one


Define trophic level.

The level of heterotroph in the food chain sequence.


How does energy flow in food chains? How does this limit the length of food chains?

-Chemical energy in carbon compounds flows through food chains through feeding. Energy released by respiration is used in living organisms and converted to heat, which is released into the abiotic environment
-90% of energy at each trophic level is lost due to usage or as heat. Each trophic level requires 10x as much energy to begin with to exist.


Define carbon fixation.

The conversion of CO2 to organic compounds by living organisms.


How is peat formed?

Peat forms when organic matter is not fully decomposed because of anaerobic conditions in waterlogged soils.
-Water fails to drain out of soil, making it waterlogged and anaerobic
-saprotrophs can't thrive in this so dead organic matter isn't fully decomposed
-increased acidity inhibits saprotrophs and methanol ends developing
-partially decomposed matter accumulates, compresses and forms a brown acidic material called peat


Explain the creation of coal. Explain the creation of oil.

-Peat is buried under other sediments. Peat is thus compressed and heated into coal.
-Mud at the bottom of seas, lakes not fully decomposed due to anaerobic environment. Matter compressed and heated as more sediment is added on. Becomes oil over time.


How is limestone formed?

-Some animal shells contain calcium carbonate.
-After organism dies, she'll is decomposed very slowly in water, resulting in limestone.


What contributes to CO2 in the atmosphere?

-Incomplete decomposition and fossilization of organic matter
-cellular respiration in saprotrophs, detritivores, producers, and other heterotrophs


What reduces CO2 concentrations in the atmosphere?



What do atmospheric CO2 concentrations affect?

-Rate of photosynthesis
-pH of seawater
-global temperature (and thus sea levels)


What are the two most significant greenhouse gases?

CO2, H2O


What gases have smaller impacts on climate? What prominent gases are not greenhouse gases and why?

-Methane and nitrous oxide have smaller impacts on climate.
-Nitrogen and oxygen are not green-house gases as they do not absorb long-wave radiation.


What type of radiation does the sun emit? What type is reflected off Earth? What do greenhouse gases do to these waves?

-Sun releases short-wave radiation
-Earth reflects long-wave radiation
-Greenhouse gases prevent long-wave radiation from leaving and absorb harmful rays.


How does global CO2 concentration correlate with global temperatures?

There is a strong, positive correlation.


What can be affected by higher temperatures?

-Increased evaporation of H2O leads to more precipitation
-Increased water temperature leads to more tropical storms


What is interbreeding and crossbreeding?

-Interbreeding is breeding of individuals of the same species
-Crossbreeding is breeding of individuals of different species