Ch. 4 Definitions (Ecology) Flashcards
Species
A group of organisms that can potentially interbreed and produce fertile offspring.
Population
A group of organisms of the same species that live in a particular area at the same time.
Community
A group of populations living and interacting in a particular area.
Ecosystem
A community and its abiotic environment.
Abiotic factors:
Non-living factors, such as pH, salinity, wind speed, type of soil, etc.
Biotic factors:
Living factors in an ecosystem, such as the plants and animals.
Autotrophic
a mode of nutrition which involves the organism making organic molecules using the abiotic environment
(‘self-nutrition’ [direct meaning])
Note: I would say ‘autotrophic’ describes organisms using this mode of nutrition, while the mode of nutrition itself is ‘autotrophy’.
Heterotrophic
a mode of nutrition in which organisms obtain organic molecules from other organisms.
(‘other-nutrition’)
See autotrophic card (heterotrophic vs. heterotrophy)
Mixotrophs
organisms which use both autotrophic and heterotrophic modes of nutrition.
Ingestion
the taking in of a substance (be it solid or liquid food, medication, toxic substances or indigestible materials)
Consumers
organisms that gain nutrients by feeding on other organisms using ingestion or absorption.
How to define ‘herbivore’, ‘carnivore’, ‘primary producer’, etc.?
With reference to where their food is in trophic levels, e.g.
Herbivores are consumers who feed solely on producers.
Primary consumers feed on producers.
Secondary consumers feed on primary consumers
Tertiary consumers feed on secondary consumers.
Carnivores are consumers who feed solely on other consumers.
Detritivores
organisms that gain nutrients by feeding on dead organic material and breaking it into smaller organic molecules VIA INTERNAL DIGESTION
Internal digestion
the process by which an organism digests its food inside of its body, usually with the aid of a digestive tract.
Saprotrophs
organisms that get their nutrients by secreting digestive enzymes into their environment to break down organic debris around them.
External digestion or extracellular digestion
the process by which organisms secrete enzymes into their environment to break down organic debris around them.
Ecology
the branch of biology where scientists study ecosystems and the interactions of the biotic and abiotic factors.
Symbiosis
‘living together’ - mutualistic, commensalistic, or parasitic interactions between populations
Mutualism
symbiotic relationship where both organisms benefit.
Commensalism
symbiotic relationship where one organism benefits and the other is unaffected.
Parasitism
symbiotic relationship where one organism benefits and the other is harmed.
Nutrient cycling
Movement of organic molecules and minerals through the food chain and back into the soil where they can be taken up by plants to re-enter the food chain.
mesocosm
tool used to model ecosystems in order to monitor and evaluate variables.
Chi squared
statistical test: are two variables (in biology, two populations) associated (each affects the other, e.g. they are dependent on one another) or not?
Used to analyse categorical data
Null hypothesis
Hypothesis that states there is no relationship between the variables being investigated, used in chi-squared tests
ecological frequency
Number of times a plant species occurs in a given number of quadrats. Frequency is usually expressed as a percentage and is sometimes called a Frequency Index.
quadrat
a tool used to measure population distribution in a given area. It is often made in a square shape.
Basically a square grid/frame, you put it on the ground and count the number of plants/animals/etc. inside it
food chain
model that shows how nutrients and energy are passed from producer to primary consumer, then secondary consumer, and so on.
It clearly shows how each organism in the chain gets its food as well as the direction the energy flows through the chain.
Trophic level
the position of an organism in a food chain (where the producer belongs to trophic level 1)
Biomass
mass of dried organic material which can be used as fuel (energy source; not literal combustion-based fuel) in an ecosystem
expressed in terms of dry weight per unit area.
Stomata
pores found on the underside of leaves which allow for gas exchange.
Anaerobic/anoxic
Without oxygen
Methanogenic archaeans
bacteria that are found in several anoxic environments and produce methane as part of the carbon cycle.
tl;dr: bacteria that produce methane
Ruminants
mammals that have a mutualistic relationship with methanogenic archaeans that help them to digest cellulose from the cell walls in the plants they eat. This creates methane, which is released as gas from the mammal.
Anything ending in ‘-genesis’:
The production of something.
E.g. acetogenesis = produce acetate, acidogenesis = produce acids, methanogenesis = produce methane
Peat
partially digested organic matter that forms in acidic, water-saturated soil. Can be gradually compressed into coal.
Fossil fuels
organic material that has been compressed over time, to form coal, oil and gas.
Lithification
the process of compressing organic matter over a long period of time until it becomes rock.
E.g. shells -> limestone
Reservoir/sink:
a place where a certain element, such as carbon, has accumulated or pooled.
Also, known as a sink when discussing nutrient cycling.
Flux
process that moves an element from one reservoir or sink to another.
Lithosphere
the portion of the Earth that consists of the crust and upper mantle.
Hydrosphere
the portion of the Earth that consists of water including oceans, lakes, ponds and rivers.
Biota
the portion of the Earth that consists of the living organisms.
Atmosphere
the layer of gases surrounding the Earth.
Greenhouse gases
gases found in the atmosphere such as water vapour, carbon dioxide, methane and nitrous oxides, that contribute to the greenhouse effect.
Radiation
energy that may be a subatomic particle, for example an electron (gamma rays) or in the form of an electromagnetic wave, for example ultraviolet radiation.
Solar radiation
energy from the sun that comes in the form of electromagnetic waves. This includes many types of waves such as visible light or ultraviolet light.
Ozone layer
layer of the Earth’s atmosphere that protects the Earth from ultraviolet radiation coming from the sun. It is not considered a greenhouse gas because it does not absorb longwave radiation.
UV/ultraviolet radiation
a type of shortwave radiation coming from the sun, but is filtered out by the ozone layer
Long-wave/long-wavelength radiation
infrared light, a type of radiation that is emitted from the Earth and its atmosphere. Examples include, microwaves and radiowaves.
Heats things up (I think).
Short-wavelength radiation
this type of radiation comes from the sun in the form of visible light and ultraviolet light. It is absorbed by the Earth and re-emitted as long-wavelength radiation.
Climate
long-term weather patterns in an area or region.
Climate change
changes in the long-term weather patterns in an area or region due to the intensified greenhouse effect.
Precautionary principle/burden of proof
The principle stating that even without concrete evidence of a causal relationship, precautionary measures should be taken to ensure that humans are not causing harm to the environment or to human health.
Basically, if you’re not sure, take the safe option.
Coral reefs
a ridge in the ocean where living coral polyps attach and secrete calcium carbonate.
Coral reefs are typically very diverse places found in warm shallow waters.
Ocean acidification
drop in pH of the ocean due to the absorption of carbon dioxide, which forms carbonic acid.
The H+ ions become dissociated from carbonic acid causing the water to become acidic.
Calcification
the process used by molluscs, crustaceans, and corals to build their shells and exoskeletons using calcium carbonate.
(Probably an arrow in the carbon cycle, although I don’t know exactly where.)
