4.1 Species and Ecosystems Flashcards
What is a species?
A species is a group of organisms that can potentially interbreed to produce fertile, viable offspring
can members from one species reproduce with another species?
Members of a single species are unable to produce fertile, viable offspring with members from a different species
What happens when two different species interbreed?
When two different species do produce offspring by cross-breeding, these hybrids are reproductively sterile (e.g. liger, mule)
What is a population?
A population is a group of organisms of the same species that are living in the same area at the same time
Can organisms that live in different regions still be considered species?
Organisms that live in different regions (i.e. different populations) are reproductively isolated and unlikely to interbreed, however are classified as the same species if interbreeding is functionally possible
What is a community?
A group of populations living together and interacting with each other within a given area
What is a habitat?
The environment in which a species normally lives, or the location of a living organism
What is an ecosystem?
A community and its abiotic environment (i.e. habitat)
What is ecology?
The study of the relationship between living organisms, or between living organisms and their environment
What ae the 3 ways organisms can obtain chemical energy?
autotrophs
heterotrophs
mixotrophs
What are autotrophs?
Synthesises its own organic molecules from simple inorganic substances (e.g. CO2, nitrates)
Where do autotrophs gain energy from?
Energy for this process is derived from sunlight (photosynthesis) or via the oxidation of inorganic molecules (chemosynthesis)
What is the term used to refer to autotrophs?
Because autotrophs synthesise their own organic molecules they are commonly referred to as producers
What are heterotrophs?
Obtains organic molecules from other organisms (either living / recently killed or their non-living remains and detritus)
What are heterotrophs referred to as?
Because heterotrophs cannot produce their own organic molecules and obtain it from other sources, they are called consumers
What are mixotrophs?
Certain unicellular organisms may on occasion use both forms of nutrition, depending on resource availability
What is an example of a mixotroph?
Euglena gracilis possess chlorophyll for photosynthesis (autotrophic) but may also feed on detritus (heterotrophic)
What are the 3 types of heterotrophs?
consumers
detritivores
saprotrophs
What are consumers?
Consumers ingest organic molecules from living or recently killed organisms
What are detritivores?
Detritivores ingest organic molecules found in the non-living remnants of organisms (e.g. detritus, humus)
What are saprotrophs?
Saprotrophs release digestive enzymes and then absorb the external products of digestion (decomposers)
In what two ways do autotrophs derive energy for the synthesis of organic molecules from simple inorganic substances?
Most autotrophs derive the energy for this process from sunlight (via photosynthesis)
Some may derive the needed energy from the oxidation of inorganic chemicals (chemosynthesis)
Where do autotrophs gain the inorganic substances from?
Autotrophs obtain the simple inorganic substances required for this process from the abiotic environment
What are examples of inorganic substances that autotrophs use?
These nutrients – including carbon, nitrogen, hydrogen, oxygen and phosphorus – are obtained from the air, water and soil
