Chapter 24 Flashcards
The expanding human population threatens (2)
- Biodiversity
- the loss of natural ecosystem
Healthy ecosystem (4)
- Purify air and water
- Decompose waste
- Recycle nutrients
- Pollinate crops
- Other individuals in its own population
- Population of other species living in the same ares
- An assemblage of species living close enough together for potential interaction is called a community
An organism’s biotic environment
An assemblage of species living close enough together for potential interaction is called a ____________.
community
__________are interactions between species. Classified according to effect organisms involved
interspecific interaction
____ interactions occur when two populations in a community compete for a common resource.
Negative/Negative (-/-)
____ interactions are mutually beneficial, such as between plants and their pollinators
Positive/Positive (+/+)
___ Interactions occur when one population benefits and the other is harmed, such as in predation
Positive/Negative (-/+)
In ______________, the population growth of a species may be limited
Interspecific competition (-/-)
In interspecific competition the population growth of a species may be limited by (2)
- The population densities of competing species
- By the density of its own population
An ecological _______ is the sum of an organism’s abiotic and biotic resources in its environments
Niche
___________ occurs when the niches of two populations overlap.
Interspecific competition
The _________________ states that if two species have an ecological niche that is too similar, the two species cannot coexist in the same place.
Competitive exclusion principle
These different species of warblers have an ecological niche that overlaps, leading to ______________,
Interspecific competition
________both species benefit from an interaction
Mutualism(+/+)
An example of mutualism includes (2)
reef-building corals and photosynthetic dinoflagellates
The photosynthetic dinoflagellates (3)
Both organisms benefits
- gain shelter in the cells of each coral polyp
- produce sugar used by the polyps
- provide at least half of the enegry used by the coral animals
refers to an interaction in which one species (the predator) kills and eats another (the prey)
Predation(+/-)
Numerous adaptations for predator avoidance have evolved in prey populations through ____________.
natural selection
Camouflage
Cryptic coloration
Cryptic coloration
A way for prey to hide from predators
Brightly colored pattern
Warning coloration
Warning coloration
-Way to warn predators that an animal has an effective chemical defense
Animals look like another species
Mimicry
is the consumption of plant part or algae by an animals
Herbivory (+/-)
Herbivores and plants undergo ___________.
coevolution
Herbivores and plants undergo coevolution (2)
- a series of reciprocal evolutionary adaptation in two species
- in which change in one species acts as a new selective force on another
A plant whose body parts have been eaten by an animal must expend energy to replace the loss
Thus, numerous defenses against herbivores have evolved in plants
Plants defenses against herbivores include
- spines and thorns
- chemical toxins
Parasites and pathogens are
(+/-)
Plants can animals can be a victims of
Parasites
internal parasites
external parasites
pathogens
Parasites, an organism that live in or on a ____ from which it obtains nutrients
Host
Internal parasites include
nematodes and tapeworms
External parasites include
mosquitoes, ticks, and aphids
Pathogens are disease-causing microscopic parasites
- Bacteria
- viruses
- fungi
- protist
_______is the feeding relationship among the various species in a community
Trophic structure
A community trophic structure determines the passage of energy and nutrients from plants and other photosynthetic organisms
- To herbivores
- then to predators
The trophic level that supports all other trophic levels consists of autotrophs, also called
producers
All organisms in trophic levels above the producers are heterotrophs, or
consumers
Primary consumers are called ______, which eat plants
herbivores
Above the level of primary consumers are carnivores, which eat the consumers from the level below
secondary consumers
tertiary consumers
quaternary consumers
Energy is lost as it moves each trophic level, limiting the number of trophic levels an ________ can sustain.
ecosystem
_____, which are often called scavengers, consume detritus, the dead material left by all trophic levels
Detritivores
_______ are prokaryotes and fungi, which screte enzymes that digest molecules in organic material and convert them into inorganic forms
Decomposers
a_______ is a network of interconnecting food chains
food web
In food webs
- consumers may eat more than one type of produce
- several species of consumers may feed on the same species of producers
A______ shows multiple interaction among producers, predators, and prey which is a better representation of what occurs in nature
foods web
_______ is concerned with the number of different species and their relative abundance in community
species diversity
Species diversity is important in ecosystems because it makes them more productive and enables them to ______________________________.
rebound much fast if faced with a disturbance
Although each of these woodlots has the same number of species,
woodlot b is considered more diverse
A___________is a species whose impact on its community is larger than its biomass or abundance indicates and occupies a niche that holds the rest of its community in place
Keystone species
some examples of keystone species in marine ecosystems include
- Pisaster sea star because they keep the population of mussels in a marine environment in check
- without Pisaster, mussels would completely dominate many marine habitats
_______: are events that damage biological communities
Disturbances
Disturbances include
Storms, fires, flood, droughts, overgrazing, or human activity
The types, frequency, and severity of disturbances varies from
community to community
after a disturbance an ecological
succession follows
________ is the colonization of a species in a given habitat after a disturbance
ecological succession
Primary succession begins in a virtually lifeless area with no soil ex:
volcanoes and glacial activity
Secondary succession occurs when a distrubance destroys an existing community but leaves the soil intact ex:
fires and floods
___________: are organisms that have been introduced into non-native habitats by humans actions
Invasive species
Invasive species
- have established themselves at the expense of native communities
- The absence of natural enemies often allow rapid population growth of invasive species
Example of invasive species include the deliberate introduction of
- rabbits into australia
- cane toads into australia
__________ include essential elements and chemicals needed throughout different levels or an ecosystem
Biogeochemicals cycles
Biogeochemical cycle include
Biotic components
Abiotic components
Biogeochemical cycles can be
-local or global
Carbon is
the major ingredient of all organic molecules
found in the atmosphere, fossil fuel, dissolved in cabon compound in ocean
carbon
The return of CO2 to the atmosphere by respiration closely balances its removal by _______________.
Photosynthesis
The carbon cycle is affected by
Burning wood and fossil fuels
Organisms require phosphorus for
nucleic acids, phospholipds, and atp
The________ does not have an atmospheric component
Phosphorus cycle
_____ are the only source of phosphorus for terrestrial ecosystem
rocks
_____ absorb phosphate ions in the soil and build them into organic compounds
Plants
Phosphates are returned to the soil by _________.
decomposers
Phosphate levels in ________ are typically low enough to be a limiting factor
aquatic ecosystem
Nitrogen is an ingredient of proteins and nucleic acids(2)
- essential to the structure and functioning of all organisms, and
- a crucial and often limiting plant nutrients
Nitrogen has two abiotic reservoirs
1) theatmosphere of which about 80% is nitrogen gas
2) soil
Nitrogen fixation (2)
- converts N2 to compounds of nitrogen that can be used by plants
- is carried out by some bacteria
Although agricultural and other managed ecosystems are necessary to supply our needs, we also depend on services provided by _________.
natural ecosystems
Healthy ecosystems (4)
- supply freshwater and some food
- recycle nutrients
- decompose wastes
- regulate climate and air quality
