DAT bio chapter 14 ecology Flashcards
Abiotic factors
nonliving elements of an
ecosystem (eg. temperature, water, light).
biotic factors
living elements of an
ecosystem (eg. plants, animals, etc.).
species
group that can interbreed and
have viable, fertile offspring.
Population:
specific species living in a
specific location.
Habitat:
type of place where a specific
organism lives. Includes other organisms
(biotic) and physical aspects (abiotic).
Ecological community:
all populations in a
given area.
Ecosystem?
all the organisms in an ecological
community (biotic), and the abiotic factors
interacting within it.
biosphere?
all ecosystems on Earth, their
interactions with each other and the
lithosphere, geosphere, hydrosphere,
atmosphere.
Density-dependent factors
depend on
population density. Becomes more significant as the population density increases. (eg. disease, resource
competition).
Density-independent factors
do not depend
on population density (eg. climate, weather).
What is organism niche?
the biotic and abiotic resources an organism uses
what is realized niche?
where it truly lives
what is fundamental niche?
the full range of environmental conditions where it could survive
What is Gause’s law
(competitive exclusion principle):
Two species cannot occupy the same niche and
maintain population levels: one will outcompete
the other.
What is resource partitioning?
allows species to coexist
What is competition?
2 species compete for the same resources
Intraspecific competition
occurs between
members of the same species (eg. two rabbits
competing for carrots).
Exploitation competition
is indirect and
occurs when resources are depleted. (eg.
cheetahs deplete gazelle population,
affecting lions).
Apparent competition
occurs when one
predator preys on two species.
Symbioisis
(living together) is a close, long-term
interaction between two organisms (symbionts).
Mutualism (+/+):
both organisms benefit (eg.
oxpecker bird eating ticks off rhino).
Commensalism (+/0):
one organism benefits
and the other is unaffected. (eg. jackal eating
tiger’s leftovers).
Parasitism (+/-):
one organism benefits at the
other’s expense. (eg. tapeworm in human
gastrointestinal tract).
food chain
linear depiction of what eats
what (eg. carrot → rabbit → fox → lion).
food web
expanded food chain depicting
interconnections between food chains.
Trophic level:
an organism’s position within
a food chain or food web.
Autotroph:
produces organic compounds
from abiotic factors (sunlight, water, CO2
,
etc.)
Heterotroph:
must ingest organic
compounds to generate energy & survive.
Invasive species:
species: non-native species that
outcompetes native species and overtakes
ecosystem.
noninvasive species
non-native species
that survives in but does not overrun an
ecosystem.
Who is at the lowest trophic level?
primary producers
Example of primary producer
autotrophs
what eats primary producers?
primary consumers
What are primary consumers?
often herbivores. they eat primary producers
What percentage of energy stored in trophic level is converted to organic tissue in the next trophic level as energy transfer
10 percent
what is the ranking going from highest biomass to smallest biomass
producers- primary consumers- secondary consumers-tertiary consumers
What do scavengers do
they are carnivores or herbivores that eat nother dead animals Ex. vultures and beetles)
examples of decomposers
Saprophytes (plants,
fungi, microorganisms) decomposers that
consume dead or decaying organic material, and
work with scavengers in organic recycling.
What is the most important decomposer
fungi and some bacteria decompose organism, forming detritus (feces and decomposing matter)
What are detritivores
worms and slugs that consume detritus, exposing more organic material for decomposers
Biotic potential:
species’ ability to undergo
its highest population growth (highest births,
lowest deaths) when conditions are ideal.
Carrying capacity:
maximum population
size an ecosystem can sustain.
K-selected species: examples
humans and large mammals long birth time few large offsprings long time to mature significant parental investment high surivival rate and reproductive age
r selected species: examples
insects, bacteria,
abundant, small offspring,
mature quickly, no parental investment, many do
not survive to reproductive age
What kind of curve is k selected>
type 1 survivorship
what kind of curve is r selected?
type 3 survivorship
Explain about type 2 survivorship curve
survival
probability is constant regardless of age (eg.
hydra, some birds & small mammals, lizards).
What is ecological succession?
process where an ecological community develops and changes over time.
When does ecological succession happen?
occurs in a new habitat or after a disturbance
What happens in primary succession?
happens after a large disturbance (volcanic eruption or on a a rocky terrian that has never supposed life)
It all happens on a substrate that completely lacks plant and animals life.
What begins primary succession
pioneer species (eg lichen, fungi, and algae or a small plant will come plant itself)
pioneer species → thin soil → vascular plants
(grasses, shrubs) → larger plants (trees) →
animals
What is the result of primary sucession?
climax community results. A steady
state is reached and a balance of species is
achieved.
What is secondary sucession?
succession occurs on terrain that has
supported life previously but lost it to a big flood or fire. Follows the same step of primary succession except it begins with grasses and shrubs
what is keystone species
Smaller number of species (lions, bears, killer whales) that keeps other species in check. NO overabundance happens due to one species.
The aquatic biome is the _____ of earths biome and it consists of ____ of earths surface
largest
75 percent
What is the aquatic biome divided into?
freshwater biomes (~3%) and saltwater biomes (~97%).
What is an estuarie?
areas where freshwater meets saltwater
How is the layers of the ocean divided
based on the amount of sunlight it receivesq
Euphotic zone
(lots of sun) closet to the surface
allows for plant survival and photsynthesis
littoral zone
area of the euphotic zone where sunlight penetrates all the way to the ocean floor
disphotic zone
(little sun) not enough sun for sufficient plant growth
Bioluminescent
species produce light here.
Aphotic zone
no light or photosynthetic
species. Some bioluminescent species. Select
fish can survive off of dead matter
descending to the ocean floor.
