2.1 Flashcards
species
a group of organisms that share common
characteristics and that interbreed to produce fertile offspring
ecology
The study of the living (biotic) and non-living
(abiotic) parts that interact within an
ecosystem
How they interact with one another
abiotic factor
non-living, physical
factors in the ecosystem that may influence
an organism or a system
exp: soil ph, humidity
they are all interdependent
population
A population is a group of organisms of the same species living in the same area at the same time
able to interbreed
if one is separated, it will form new species
community
A group of populations of different species living
and interacting with each other in a habitat
ecosystem
interaction between organisms and the
environment is the key
habitat
The characteristics of the type of environment
where an organism normally lives
keystone species
Species that have especially great impacts on other
community members and on the community’s
identity
species yang penting untuk sustain ecosystem
If keystone species are removed, communities
change greatly.
species that are crucial to
the maintenance of their ecosystem
Keystone is often, but not always, PREDATOR
exp: sea otter, sea urchin, kelp (seaweed)
sea otter makan sea urchin
sea urchin makan batang kelp
kalau sea otter takde, kelp habis kena makan degn sea urchin
then habitat tu takde producer
explain how population change
contoh cicak
ancestral amphibians population were isolated by different geographic factors
different ecosystem made them acquiring new characteristics in order for them to survive in that habitat
overtime, they evolve into new species
exp: body colours, body size
niche
describes the particular set of abiotic and biotic
conditions and resources which an organism or population responds
ada kena mengena dgn trophic level
exp: How the species obtains its food and Temperature range
competitive exclusion principle/Gause’s Law
2 species of identical niche cant survive in the same habitat
Experiment on P. caudatum and P. aurelia
When cultured separately, both thrived.
When cultured together, the numbers of both reduced, but P. caudatum was reduced disproportionately.
One will either die out or migrate, or
they will adapt to carve out separate
resources niches (niche partitioning)
type of niche
fundamental niche
full range of conditions and
resources in which a species could survive and reproduce.
realised niche
the actual conditions and resources in which a species
exists due to biotic interactions
occupy a portion of fundamental niche
sometimes influence with interaction with other organisms
niche vs habitat
niche explains the role of organisms (primary consumer etc.) and organisms behaviour
habitat explains where organisms live
predation
hunting
herbivory
hunting plant
mutualism
two species benefit
parasitsm
one species depends on another for nutrition, harming the host organisms
disease
caused by pathogens
reduce the population of the infected organisms
amensalism
one unaffected the other harmed
(antonym commensalism)
neutralism
two organisms do not affect each other. No relationship
competition
intraspecific
competition between individuals from the same species
exp: rhinoceros (mate)
interspecific
competition between different species
exp: lion and hyenas (food/territory)
Population Dynamics
the study of change in population over time
J curve
without limiting factors
aka exponential growth
populations exceed carrying capacity (overshoot)
usually **R strategy **organisms (microbes)
S curve
**lag phase
exponential phase **(abundant food sources)
transitional phase (competition)
plateau phase (reaches carrying capacity/no longer growth)
when exponential growth slows and reaches carrying capacity this called environmental resistance
why population fluctuate around carrying capacity?
bcs negative feedback due to overshoot of birth and bcs below k due to death
dieback
sudden collapse/pollution crash occurs when there is limiting factor
overshoot
population exceed carrying capacity
carrying capacity
The maximum number of organisms of a single species that
an ecosystem can sustainably support
density dependent
Biotic
Will increase or decrease the carrying capacity of a
population based on the size of the population
Negative feedback mechanisms - e.g. predator-prey
relationship
(intraspecific) - within a species
Food supply
Territory
(interspecific) - between species
Predation
Disease
density independent
Will increase or decrease the carrying capacity regardless of the size of the population
abiotic
exp: flood, climate change
limiting factor
Factors in an ecosystem that limit the population size if there is too much or too little of it.
reduce populaton growth
can be divided into density dependent and density independent
slow population growth as it reaches carrying capacity k
exp: sunlight, precipitation, salinity
k strategy (4 only)
favoured environmental: stable
reproduction rate: slow
size of population: typically small
tendency of emigrate: typically settled
lifespan: long
competition: strong competitor
mortality rate: low
r strategy
favoured environmetal: variable and unstable
reproduction rate: fast
size of population: variable but often below the carrying capacity
tendency to emigrate: often
lifespan: short
competition: poor competitor
mortality rate: high
