Chapter 13 - Ecology Flashcards
ecology is the study of
interactions between organisms and their environment
environment encompasses
all that is external to organism and necessary for existence
organism’s environment contains two components
abiotic (physical) biotic (living)
abiotic
physical (non-living)
biotic
living
physical (abiotic) environment includes (5)
climate temperature availability of light availability of water local topology
living (biotic) environment includes
all living things which directly or indirectly influence life of organism
the relationship that exists between organisms is a part of the
biotic environment
levels of biological organization
organism population communities ecosystem biosphere
organism
individual unit of ecological system
organism is composed of
smaller units
organism contains ____ which are made up of ____
organ systems; organs
organs are formed from
tissues
tissues are formed from
cells
cells are formed from
molecules
molecules are formed from
atoms
atoms are formed from
sub-atomic particles
population is a group of
organisms of the SAME species
population is a group of organisms of ____ species
same
population is a group of organisms of the SAME species _____
living together in a given location
examples of populations include: dandelions; flies; minnows; lions;
on a lawn; in a barn; in a pond; in a grassland area
species
group of similar organisms capable of reproducing fertile offspring
environmental factors such as _____, ____, ____ aid in maintaining populations are relatively constant levels
nutrients, water, sunlight limitations
a community consists of
biotic environment populations of different plants and animal species interacting with each other in a given environment
biotic community includes
only populations and not physical environment
ecosystem includes
community and environment
community contains populations from
all 5 kingdoms
5 kingdoms
monera, protists, plants, fungi, animals
within an ecosystem, all 5 kingdoms depend on
each other for survival
lawn contains
dandelions grasses mushrooms earthworms nematodes bacteria
pond contains
dragonflies algae minnows insect larvae
forest contains
moss pine bacteria lichens ferns deer chipmunks spiders foxes
sea contains
fish whales plankton
ecosystem (ecological community) encompasses the interaction between
living biotic communities and nonliving environment
in studying the ecosystem, the biologist look sat the effects of the
biotic community on the env. and vise versa
examples of communities and of ecosystems
lawn pond forest sea
biosphere includes
all portions of the planet which supports life
portions of the planet which support life (3)
atmosphere lithosphere hydrosphere
lithosphere
rock and soil surface
hydrosphere
oceans
the biosphere extends ____ beneath the earth’s surface
a few feet
the biosphere extends ____ into the sea
several miles
the biosphere extends _____ into the atmosphere
several miles
parts of the physical environment (5)
water temperature sunlight oxygen supply substratum (soil or rock)
major component of the internal environment of all living things
water
water may be readily available or the organism may
possess adaptations for storage and conservation of the water
temperature must be
maintained at an optimal level
at temperatures below 0C and above 100C, _____ is destroyed
protoplasm
organisms have _____ necessary for protection against temp. extremes
adaptations
temperature of a geographic location depends on its
latitude altitude
as one approaches the colder polar regions and the colder regions of a mountain top
the same changes in habitat occur
ultimate source of energy for all organisms
sunlight
green plants must compete for _____ in forests
sunlight
broad leaves, branching, growing to greater height, produce vine growths are examples of
adaptations of plants to capture as much sunlight as possible
photic zone (water) is defined as
top layer through which light can penetrate
the photic zone in water is where all
aquatic photosynthetic activity takes place
aphotic zone (water)
only animal and heterotrophic life exist
oxygen supply and terrestrial life
no problem - air contains 20% oxygen
aquatic plants and animals must utilize (oxygen supply)
small amount of oxygen dissolved in water
pollution and oxygen supply in water
pollution can significantly lower oxygen content in water and threaten aquatic life
substratum determines the nature of
plant and animal life in the soil
soil is affected by (4)
acidity (pH) texture minerals humus
most suited for growth in acid soil (2)
rhododendrons pines
this may make soil pH too low for most plant growth
rain
____ and ___ determine the water-holding capacity of soil
texture clay content
willows require ____ soil
moist
most plants grow well in
loams
loams contain
high percentages of each type of soil
examples of minerals that affect the type of vegetation that can be supported (2)
nitrates phosphates
beach sand is unable to support plant life because it has been
leached of all minerals
humus quantity is determined by
amount of decaying plant and animal life in the soil
organisms belonging to the same or different species influences
each other’s development
living things interact with
other living organisms and with their physical environment
interactions between constituents of an ecosystem involve a _____ of energy and materials
cyclic flow
interactions within the ecosystem
niche nutritional interactions interspecific interactions intraspecific interactions interactions between organisms and their environment
the niche defines the
functional role of an organism in its ecosystem
habitat
physical place where an organism lives
relationship between habitat and niche
characteristics of habitat help define the niche
the concept of the niche embodies
every aspect of an organisms existence
the niche describes
what the organism eats where and how it obtains food the nature of its parasites and predators where and how it reproduces
by definition, two species _____ niche
can never occupy the same
organisms occupying the same niche
compete for limited resources
examples of limited resources in a niche
food water light oxygen space minerals reproductive sites
may be multiple organisms in the same niche, but they are
the same species - same requirements
a species can be _____ by the niche it occupies
identified
species occupying the similar niches use ____ in common
at least one resources
as a result of species occupying the same niche having at least one resource in common,
they will compete for that resource
competition among species for a common resource can have these outcomes
extinction elimination in environment divergence
extinction (outcome of species competition for common resource)
one species may be competitively superior —> drive other to extinction
elimination in environment (outcome of species competition for common resource)
one species may be competitively superior in one region while the other is superior in other regions elimination of one species in one region and the other in other regions
divergence (outcome of species competition for common resource)
two species may rapidly evolve in divergent direction under strong selection pressure resulting from intense competition two species evolve greater differences in their niches
examples of nutritional interactions within the ecosystem
autotrophs heterotrophs herbivores carnivores omnivores
autotrophs
organisms that manufacture own food green plants utilize energy of sun to manufacture food
chemosynthetic bacteria are examples of
autotrophs
chemosynthetic bacteria as autotrophs
obtain energy from oxidation of inorganic sulfur, iron, nitrogen compounds
heterotrophs
cannot synthesize their own food must depend on autotrophs or other heterotrophs in ecosystem to obtain food and energy
herbivores consume
only plants or plant food
the toughness of cellulose-containing plant tissues las led to the development of (herbivores)
structures for crushing and grinding that can extract plant fluid
herbivores have long digestive tracts that provide
greater surface area and time for digestion
herbivores cannot ______ most of the food the consume
digest
_____ capable of digesting cellulose inhabit the digestive tracts of herbivores
symbiotic bacteria capable of digesting cellulose
symbiotic bacteria (that inhabit the digestive tracts of herbivores)
are capable of digesting cellulose
symbiotic bacteria that inhabit the digestive tracts of herbivores allow for the breakdown and utilization of
cellulose
herbivores are more adept in ______ than carnivores because they are often prey
defense
many herbivores, like cows and horses, have hoofs instead of toes for
faster movement on the grasslands
herbivores have _____ adapted for cutting their food
incisors
herbivores have ____ adapted for grinding their food
molars
carnivores eat only
other animals
carnivores possess _____ and _____ for tearing flesh
pointed teeth and fang-like canine teeth
carnivores have shorter digestive tracts due to the
easier digestibility of animal food
omnivores eat
both animals and plants
community is an _____ of species, which are dependent upon one another for survival
integrated system
major types of interspecific interactions
symbiosis predation saprophytism scavenging
symbiosis
symbionts live together in intimate, often permanent association which may or may not be beneficial to both participants
some symbiotic relationships are
obligatory
obligatory symbiotic relationship
one or both organisms cannot survive without the other
symbiotic relationships are classified according to the
benefits the symbionts receive
types of symbiotic relationships
commensalism mutualism parasitism
commensalism
1 0 (one organism is benefited by the association and the other is not affected)
in commensalism, the host
neither discourages nor fosters the relationship
examples of commensalism: remora and shark
remora (sharksucker) attaches itself by a holdfast device to the underside of a shark remora obtains: food the shark discards wide geographic dispersal protection from enemies shark is totally indifferent
example of commensalism: barnacle and whale
barnacle is a sessile crustacean attaches to the whale and obtains wider feeding opportunities through the migrations of the whale
mutualism
1 1 symbiotic relationship from which both organisms derive some benefit
example of mutualism: tick bird and rhinoceros
bird receives food in the form of ticks on the skin of the rhino rhino has its ticks removed and is warned of danger by rapid departure of the bird
example of mutualism: lichen
very intimate association between fungus and algae found on rocks and tree barks
in lichen, the _____ produces good for itself and the fungus by ______
green algae; photosynthesis
the meshes of fungal thread _______ algae and _____ rain water
supports; conserves
in addition to supporting the algae and conserving rain water, the fungus also provides _____ and ______ for the algae
carbon dioxide; nitrogenous wastes
carbon dioxide, nitrogenous wastes, support and rain water are all needed for _____ and ______
photosynthesis; protein synthesis
lichens are ______ organisms in the order of ecological succession on bare rock
pioneer
example of mutualism: nitrogen-fixing bacteria and legumes
nitrogen-fixing bacteria invade the roots of legumes and infected cells grow to form root nodules
in the nodule, the legume provides _____ for the bacteria and the bacteria _____ nitrogen
nutrients; fixes
the bacteria fixes nitrogen by changing it to a _____
soluble nitrate
soluble nitrate is a mineral essential for _______ by the plant
protein synthesis
nitrogen fixing bacteria are a major source of
usable nitrogen
usable nitrogen is needed by
all plants and animals
example of mutualism: protozoa and termites
termites chew and ingest wood but are unable to digest cellulose. protozoa in the digestive tract of the termite secrete an enzyme which digests the cellulose
termites chew and ingest wood but are unable to digest
cellulose
_____ in the digestive tract of the termite secrete an enzyme which digests cellulose
protozoa
both protozoa and termites share the _____
carbohydrates
as a result of the protozoa-termites mutualism, the protozoan is guaranteed ______ and _____
protection; steady food supply
in the protozoa-termites mutualism, the termite is able to obtain
nourishment from the ingested wood
example of mutualism: intestinal bacteria and humans
bacteria utilize some of the food material not fully digested by humans and manufacture vitamin K
parasitism
-1 1
a parasite benefits at the expense of the
host
parasitism exists when
competition for food is most intense
few autotrophs (green plants) exist as
parasites exception: mistletoe
parasitism flourishes among organisms such as
bacteria fungi animals
ectoparasites
parasites that cling to the exterior surface of the host using suckers or clamps
ectoparasites cling to the exterior surface of the host using
suckers or clamps
ectoparasites may bore through the skin and
suck out blood and nutrients
examples of ectoparasites
leeches ticks sea lampreys
endoparasites
live within the host
in order to gain entry, endoparasites must pass through
defenses: skin digestive juices antibodies white blood cells
parasites possess special _____ to overcome defenses
adaptations
parasitism is ______ and _______ for the parasite
advantageous; efficient
the parasite lives with minimum
expenditure of energy
parasites may even have _____ of their own
parasites
mammal may have parasitic worms which are parasitized by bacteria which are victims of
bacteriophages
all viruses are
parasites
structure of virus
nucleic acids surrounded by a protein coat
viruses are _____ outside the host
nonfunctional
upon entry of the viral nucleic acid into the host, the virus
takes over the host cell functions and redirects them into replication of itself
most _____ are chemosynthetic or saprophytic
bacteria
saprophytic
bacteria of decay
diphtheria is parasitic upon
man
anthrax is parasitic upon
sheep
TB is parasitic upon
cows or man
most fungi are
saprophytic
ringworm is parasitic on
man
the tapeworm is parasitic on
man
successful parasites do not
kill their hosts
killing the host would lead to ____ of the parasite
death
the more dangerous the parasite, the less chance it will
survive
types of parasitism
virus and host cell disease bacteria and animals disease fungi and animals worms and animals
predators are free-living organisms which feed on
other living organisms
predation includes both
herbivores and carnivores
the predator may ______ the numbers or distribution of the prey
severely limit
as a result of predation, the prey may become
extinct
if the predator is scarce or commonly uses another source of food, it may
slightly affect the prey
the predator aids in controlling
the number of the prey,
although the predator aids in controlling the number of the prey, it does not so as to
endanger the existence of the prey population
predator-prey relationships evolve towards
a balance in which the predator is a regulatory influence on the prey, but not a threat to it’s survival
examples of predators
hawk lion humans Venus flytrap
saprophytes include
protists and fungi that decompose (digest) dead organic matter externally and absorb the nutrients
saprophytes constitute a vital link in the
cycling of material within the ecosystem
examples of saprophytes
mold mushrooms bacteria of decay slime molds
scavengers
animals which consume dead animals
because scavengers at dead animals, they require no adaptations for
hunting and killing their prey
decomposers such as bacteria of decay may be considered
scavengers
examples of scavengers
vulture hyena
example of both a scavenger and a predator
snapping turtle
competition is not restricted to interspecific interactions
may also be intraspecific
individuals belonging to the same species utilize the same
resources
if a particular resource is limited, organisms must
compete
members of the same species compete but they must also
cooperate
intraspecific cooperation maybe extensive or nearly nonexistent
extensive vs nonexistent
extensive intraspecific cooperation
formation of societies in animal species
competition is a chief disruptive force of intraspecific ______
cooperation
cohesive forces (intraspecific interactions)
reproduction protection from predators destructive weather
osmoregulation
animals have developed many adaptations for maintaining their internal osmolarity and conserving water
saltwater fish live in a
hyperosmotic environment
hyperosmotic environment and saltwater fish
causes them to lose water and take in salt
saltwater fish, due to hyperosmotic environment, are constantly in danger of
dehydration and must compensate
saltwater fish compensate for their hyperosmotic environment by cnostantly _____ and ______
constantly drinking and active excretion of salt across gills
freshwater fish live in a ______ environment
hypoosmotic
hypoosmotic environment causes fish to
intake excess water
freshwater fish intake of excess water causes excessive
salt loss
saltwater fish correct the excess water intake and excessive salt loss by _____, _____, _____
seldom drinking absorbing salts through the gills excreting dilute urine
in order to conserve water, insects
excrete solid uric acid crystals
desert animals possess ______ for avoiding desiccation (drying up)
adaptations
adaptation of camel to avoid deseccation
can tolerate a wide range of temperatures fat layers in regions which are exposed to solar radiation
adaptation of horned toad to desert the thick scaly skin prevents
water loss
other forms of adaptation to the desert
burrow in the sand during the day and search for food at night — avoiding intense heat (which causes water loss)
plants possess adaptations for conservation of water
in addition to animals
in order to prevent water loss, non-desert land plants have ____ on leaf surfaces and ____ on the lower leaf surfaces
waxy cuticles; stomata
in order to prevent water loss in the winter, plants
shed their leaves
in order to prevent water loss, desert plants have extensive
root systems
desert plants have ____ to store water
fleshy stems
desert plants have ____ to limit water loss
spiny leaves
in addition, dessert leaves have extra thick ____ to prevent water loss and very few _____
cuticles; stomata
cellular respiration transfers energy derived from the oxidation of carbs into
high-energy bonds of ATP
______ of the energy derived from oxidation of carbs via cellular respiration is transferred into high-energy bonds of ATP
only a fraction
60% of the total energy derived from oxidation of carbs (cellular respiration) is given off as
heat
poikilothermic
“cold-blooded”; most of the heat energy escapes to environment
vast majority of animals are (thermoregulation)
cold-blooded - poikilothermic
body temperature of poikilotherms is very close to that of the
surroundings
organism’s metabolism is closely tied to its
body temperature
since organism’s metabolism is closely tied to its body temp - activity of a poikilothermic animals is radically affected by the
environment
as temperature rises, poikilotherms become
active
as temperatures fall, poikilotherms become
sluggish and lethargic
homeothermic
warm-blooded
homeothermic animals
mammals; birds
homeothermic animals have evolved physical mechanisms that allow them to
make use of the heat produced as a consequence of respiration
physical adaptations like fat, hair and feathers
retard heat loss
homeotherms maintain
constant body temperatures
the body temps of homeotherms are _____ than the environment
higher
homeotherms are ____ dependent upon environmental temp than poikilotherms
less
because homeotherms are less dependent on the environmental temp than poikilotherms, they are able to inhabit
a comparatively wider range of environments
all living things require ____ to carry on their life functions
energy
food chain/web
complex pathways involved in transfer of energy through the living components of the ecosystem (biotic community)
food chain/web involves the _____ community
biotic
energy from the sun enters living systems through photosynthetic production of ______ by _____
glucose; green plants
within the food chain, energy is transferred from original sources in green plants —>
through a series of organisms, via consumption —-> decomposition
food chain groups
producers primary consumers secondary consumers tertiary consumers decomposers
producers
autotrophic green plants chemosynthetic bacteria
producers utilize energy of the sun and simple raw materials to manufacture
carbs, proteins, lipids
examples of simple raw materials producers use for energy
carbon dioxide water minerals
autotrophic green plants and chemosynthetic bacteria utilize energy of the
sun and simple raw materials
for producers, the radiant energy of the sun is
captured and stored in the C-H bond
producers always form the ______ in any food chain
initial step
typical producer
wheat plant
primary consumers
herbivores - animals that consume green plants
examples of primary consumers (herbivores)
cow grasshopper elephant
secondary consumers
carnivores - animals that consume primary consumers
examples of secondary consumers
frogs tigers dragonflies
tertiary consumers
feed on secondary consumers
decomposers include
saprophytic organisms organisms of decay
examples of saprophytic organisms and organisms of decay
bacteria fungi
producers and consumers concentrate and organize materials of the environment into
complex living substances
living things give off ____ during their lifetime and eventually _____
wastes; die
bacteria and fungi decompose the
organic wastes and dead tissues to simpler compounds
bacteria and fungi decompose organic wastes and dead tissues into simpler compounds:
nitrates phosphates
the simpler compounds reduced by decomposers are
returned to the environment to be used again by living organisms
material cycles involve
nitrogen carbon water
food chain is not linear, it is
a web
almost every species is consumed by (food web)
one or more species
food web is a result of
series of branches and cross-branches among all the food chains of a community to form a web
stability in the community is fostered by (food web)
greater number of pathways in a community food web
example of a food web: owls, rabbits, mice
owls eat rabbits if rabbits died from disease —> more vegetation for mice mice thrive owls eat mice rabbit population can re-grow while owls focus on mice
with a constant input of _____ from the sun, an ecosystem would run down
energy
as food is transferred from one level of energy to the next, a transfer of ____ occurs
energy
every energy transfer involves (2nd law of thermodynamics)
loss of energy
energy transfer involves energy loss - in addition, energy is lost because
each level of the food chain utilizes some of the energy it obtains from the food
each level of the food chain utilizes some of the energy it obtains from the food for
its own metabolism (to support life functions)
in the food pyramid, energy is lost via
- transfer 2. metabolism 3. heat
a pyramid of energy is a fundamental property of all
ecosystems at all levels
each member of a food chain utilizes some of the energy it obtains from its food for _____ and loses some additional energy in the form of _____
metabolism; heat
since there is a loss of energy at each feeding level, the producer organism at the base of the pyramid contains
the most energy
less energy is available for _____ and even less for _____. (pyramid of energy)
secondary; tertiary
the least amount of energy is available at the
top of the pyramid
organisms at the upper level of the food chain derive their food energy from
organisms at lower levels
since organisms at the upper level of the food chain derive their food energy from organisms at lower levels, and since energy is lost from one level to the next, each level can
support a successively smaller biomass
300 pounds of foliage (producer) may support 125 lb of insects which may support 50 pounds of insectivorous hens who in turn will only sustain 25 lb of
hawks
consumer organisms that are higher in the food chain are usually _____, _____ than those further down
larger and heavier
since higher organisms are larger and heavier than lower ones, and the lower organisms have a greater total mass, there must be
a greater amount of lower level organisms
a large bass eats tiny minnows but eats
many of them
Pyramid of Numbers: 5 levels
Level 1: Producer Level 2: Primary Consumer Level 3: Secondary Consumer Level 4: Tertiary Consumer Level 5: Final Consumer
As the pyramid ascends, there is (3) (pyramid of numbers)
less energy content less mass fewer numbers of organisms
many material cycles are accomplished through the action of
scavengers and decomposers
when material is cycled, it passes from organic form to _____ then back again
inorganic
types of material cycles
- nitrogen cycle 2. carbon cycle 3. other
nitrogen is an essential component of ____ and _____ (nitrogen cycle)
amino acids nucleic acids
amino acids and nucleic acids are the ____ for all living things (nitrogen cycle)
building blocks
there is a ____ amount of nitrogen on earth (nitrogen cycle)
finite
since there is a finite amount of nitrogen on earth, it need be (nitrogen cycle)
recovered and recycled
elemental nitrogen is chemically ____ (nitrogen cycle)
inert
elemental nitrogen cannot be used by (nitrogen cycle)
most living organisms
these two things change the nitrogen to the usable, soluble nitrates (nitrogen cycle)
lightning nitrogen-fixing bacteria in the roots of legumes
nitrates are absorbed by (nitrogen cycle)
plants
once absorbed by plants, nitrates are used to synthesize (nitrogen cycle)
nucleic acids plant proteins
animals eat plants and synthesize specific animal proteins from the (nitrogen cycle)
plant proteins
both plants and animals give off ____ and eventually _____ (nitrogen cycle)
wastes; die
nitrogen is locked up in ____ and _____ of animals (nitrogen cycle)
wastes; dead tissues
the nitrogen locked up in the wastes and dead tissues of animals is released by action of the (nitrogen cycle)
bacteria of decay
bacteria of decay converts the proteins from dead animals into (nitrogen cycle)
ammonia
the ammonia has ___ fates (nitrogen cycle)
2
fate 1 of ammonia (nitrogen cycle)
nitrified to nitrites
ammonia can be nitrified to nitrites by action of
chemosynthetic bacteria
once ammonia is nitrified to nitrites by chemosynthetic bacteria, it is
nitrified to nitrates
ammonia is nitrified to nitrates by action of
nitrifying bacteria
fate 2 of ammonia
dinitrification
denitrification
NH3 —> N2 ammonia broken down to release free nitrogen
N2 in the nitrogen cycle
beginning: free nitrogen in the atmosphere
4 types of bacteria involved in nitrogen cycle
decay nitrifying denitrifying nitrogen-fixing
bacteria have _____ use for excretory ammonia, nitrates, nitrites and nitrogen they produce
no use
excretory ammonia, nitrites, nitrates, nitrogen produced by bacteria are essential for
existence of other living organisms
free nitrogen in the atmosphere, N2 + nitrogen fixing bacteria on roots of legumes —->
nitrates, NO3-
nitrates, NO3- + absorption by green plants —>
plant protein synthesis + nucleic acid synthesis
plant protein synthesis + ingestion and digestion of plants by animals —->
animal protein synthesis from plant proteins
plant waste + dead tissue —>
ammonia
animal waste + dead tissue —->
ammonia
plant protein synthesis —>
ammonia
ammonia, NH3 + nitrifying bacteria, chemosynthesis —->
nitrites, NO2
nitrites, NO2 + nitrifying bacteria, chemosynthesis —>
nitrites, NO3-
gaseous CO2 enters the living world when (carbon cycle)
plants use it to produce glucose via photosynthesis
plants use glucose to make (carbon cycle)
starch proteins fat
plants use _____ to make starch, proteins, fat (carbon cycle)
glucose
in plants: CO2 —> glucose —> (carbon cycle)
starch, proteins, fats
animals eat plants and use the digested nutrients to form (carbon cycle)
carbs fats proteins
carbs, fats, proteins used as fuel in ____ in plants and animals (carbon cycle)
respiration
metabolically produced CO2 is (carbon cycle)
released into air
CO2 not released into air remains (carbon cycle)
locked within an organism until its death
decay processes by bacteria return the CO2 into the (carbon cycle)
air
organic compounds in plants + respiration —> (carbon cycle)
CO2 in atmosphere
organic compounds in animals and their wastes + respiration —->
CO2 in atmosphere
organic compounds in animals and their wastes + bacteria of decay —>
CO2 in atmosphere
organic compounds in plants + ingestion and digestion in animals —>
organic compounds in animals and their wastes
CO2 in atmosphere + photosynthesis —>
organic compounds in plants
other cycles recycle
water oxygen phosphorus
all things that are recycled are ___ and ____
finite; used by all living things
all substances that are cycled must be returned by the biotic community to the _____ so they can be reused
environment
an ecosystem is ____ sustaining
self
because an ecosystem is self-sustaining, it will be stable if the ____ and ____ are stable
biotic and biotic conditions
a stable ecosystem requires (2)
- a constant energy source 2. living system incorporating this energy into organic compounds
cycling
cycle of materials between living system and its environment
climax community
stable, living (biotic) part of the ecosystem in which populations exist in balance with each other and with the environment
type of climax community depends on all abiotic factors:
rainfall soil conditions temperature shade
climax community persists until
major climactic or major geological change disturbs abiotic factors or major biotic change affects populations
examples of major biotic change
disease mutations
once equilibrium is upset
new conditions are produced new communities established in ecosystem
ecological succession
orderly process by which one biotic community replaces or succeeds another until a climax community is established
sere
community stage
each community stage, or sere, in an ecological succession is identified by a
dominant species
dominant species which identifies community stage in ecological succession
species which exerts control over other species that are present
dominant species in grassland community
grass
changes occur in ecological succession because
each community that establishes itself changes the environment
each new community that establishes itself in ecological succession makes the environment
more unfavorable for itself more favorable for the community that is to succeed it
successive communities are composed of
populations that are able to exist under the new conditions
eventually, a stage arises in which a population alters the environment in such a way that the original conditions giving rise to the population are
recreated
climax community is reached when
a stage arises in which a population alters the environment in such a way that the original conditions giving rise to the population are recreated and replacement stops
ecological steady state
climax community
the climax community is permanent in the ecosystem unless
the abiotic factors are drastically altered by climactic or geographic upheavels
if the abiotic factors are drastically altered by climactic or geographic upheavels,
a new series of succession is intiated
ecological succession in a barren rocky area - might be barren as a result of
a severe forest fire
a pioneer organisms in a barren rocky area may be (northeastern US)
lichen
lichen
association between an algae and a fungus that can live on a rocky surface
lichens produce
acids
acids produced by the lichens
attack the rocks help form soil
lichens thrive only on
solid surface
as a result of the new formation of soil, conditions for lichens
worsened
the new conditions - rocks + soil formation are good for
mosses
after the lichens, airborne spores of mosses
land on the soil and germinate
the result of the airborne spores of mosses germinating is
a new sere, with moss as the dominant species
as remains of the moss build up the soil more, _____ and then ______ become ______
annual grasses then perennial grasses with deeper roots become the dominant species
with time, after grasses are dominant, we find ____ and then ____
shrubs; trees
first trees
sun loving: gray birch, poplar
more and more trees means competition for
sun
as competition for sun increases, the earlier trees are replaced with
white pine
final dominant species (northeastern US)
maples and beeches
the climax community of maples and beeches is established because they grow in
deep shade
the growth of maples and beeches produces
the same conditions that originally favored their appearance
since the growth of maples and beeches produces the same conditions that originally favored their appearance, this community
remains for thousands of years
in the final maple-beech community you would find (which animals?)
boxes deer chipmunks plant-eating insects
one forest fire can
kill the entire community
if the entire community is wiped out by a forest fire, ecological succession
starts all over again commencing with the lichen and bare rock
starts all over again commencing with the lichen and bare rock
physical factors - temperature, nature of soil, rainfall, etc
because the dominant species of a climax community depends on the physical factors, the climax community in new york state in higher elevations is ______ than the climax community in lower elevations
different
claimx community in new york state in higher elevations
hemlock-beech-maple
climax plant at lower elevations
oak-hickory
cold maine climax community
pine
wet areas of wisconsin climax community
cypress
sandy new jersey climax community
pine
cold, windy mountain top climax community
scrub oak
ecological succession in a pond, step 1:
pond: plants - algae, pondweed animals: protozoa, water insects, small fish
ecological succession in a pond, step 2:
shallow water-pond fills in: reeds, cattails, water lilies
ecological succession in a pond, step 3:
moist land: grass, herbs, shrubs, willow trees animals - frogs, snakes
ecological succession in a pond, step 4:
woodland: climax tree - pine or oak
terrestrial biomes - types
desert biome grassland biome tropical rain forest biome temperate deciduous forest biome temperate coniferous forest biome taiga biome tundra biome polar region
evolutionary origin of plants and animals can be traced to the
seas
adaptations for animals to survive on land (origins traced to sea)
- lack of water 2. lack of food and supporting medium 3. varying temperature 4. varying composition of soil
oceans have relatively ______ temperatures, as compared to land
constant
salt composition of oceans is
definite
conditions in different terrestrial and climate regions selected for plants and animals possessing
suitable adaptations
each geographic region is inhabited by a
biome
biome
distinct community inhabiting geographic region
land biomes characterized and named according to
climax vegetation
climax vegetation
vegetation that is dominant and stable after years of evolutionary development
plants are important as _____ producers
food
since plants are important as food producers, determine the
nature of the inhabiting animal population
because the plants determine the animals, the climax vegetation determines the
climax animal population
desert biome receives ______ rain every year
less than 10 inches
rain in desert biomes is
concentrated (few heavy cloudbursts)
growing season in desert is
days after rainfalls
____ plants and ____ animals inhabit the desert
small; small
most deserve plants _____ water actively
conserve
types of desert plants
cactus sagebrush mesquite
desert animals live in
burrows
examples of desert animals
insects lizards
birds and mammals found in the desert have developed
adaptations for maintaining constant body temperatures
examples of deserts
sahara in africa gobi in asia
grasslands are characterized by ____ rainfall
low
grasslands get ____ of rainfall every year
10-30 inches
grasslands provide no shelter for _____ from _____
herbivorous mammals; carnivorous predators
examples of herbivorous mammals inhabiting grasslands
bison antelope cattle zebra
animals that inhabit grasslands have developed
long legs hooves
examples of grasslands
prairies east of rockies steppes of ukraine pampas of argentina
rain forests are also known as
jungles
rain forests are characterized by
high temperatures torrential rains
climax community of rainforest includes (vegetation)
dense growth of vegetation does not shed leaves
vegetation inhabiting rain forests
epiphytes (plants growing on other plants)
epiphytes
plants growing on other plants
animals inhabiting rain forests
monkeys lizards snakes birds
in a rain forest, trees grow
closely together
in a rain forest, sunlight
hardly reaches the floor
the floor of the rain forest is inhabited by
saprophytes
saprophytes live off of
dead organic matter
tropical rain forests found in
central africa central america amazon basin southeast asia
temperate deciduous forests characterized by
cold winters warm summers moderate rainfall
trees characteristic of temperate deciduous forests
beech maple oak willows
beech maple oak willows all do this during the winter
shed leaves
animals in temperate deciduous forest
deer fox woodchuck squirrel
examples of temperate deciduous forest
northeast US central-eastern US central europe
temperate coniferous forests characterized by
cold, dry
trees of temperate coniferous forests
fir pine spruce
vegetation of temperate coniferous forests has evolved adaptations for
water conservation
examples of vegetation adaptations for water conservation
needle-shaped leaves
temperate coniferous forests found in
norther US souther canada
taiga receives ____ rainfall than temperate forests
less
taigas characterized by
long cold winters
trees in taiga
single coniferous tree: spruce
forest floors of taiga contain
moss; lichens
chief animal of taiga
moose
other animals in taiga
black bear wolf some birds
taigas located in
northern canada northern russia
tundra characterized by
treeless, frozen plain
tundra is found
between taiga and northern ice-sheets
tundra summer
very short
as a result of the very short summer, the tundra has a
very short growing season
during the very short growing season of the tundra, the ground
becomes wet and marshy
vegetation of the tundra
lichens moss
animals of the tundra
arctic hens polar bears musk oxen
polar region characterized by
frozen area
polar vegetation and animals
no vegetation no polar vegetation and animals
animals that do inhabit the polar regions generally live near
polar oceans
sequence of biome between equator and poles is comparable to sequence of regions on
mountains
nature of biomes determined by
temperatures and rainfall
base of mountain resembles biome of
temperate deciduous forest
as one ascends the mountain, one would pass (biomes)
coniferous like biome taiga like biome tundra like biome polar like biome
water covers over ____ % of the earth
70
most of the earth’s plant and animal life is found in the
water
____ % of the earth’s food and oxygen production (photosynthesis) takes place in the water
90
aquatic biomes and terrestrial biomes have _____ criteria for classification
different
plants have ____ controlling influence of aquatic biomes compared to their role in terrestrial biomes
a little
aquatic areas are the ______ stable ecosystems
most
the conditions affecting temperature, amount of available oxygen and CO2, amount of suspended or dissolved materials are ____ and show _____
stable over very large areas; little tendency to change
as a result of the most stable ecosystems the aquatic food webs and communities are
stable
two types of major aquatic biomes
marine fresh water
the oceans connect to form
one major body of water
the major body of water formed by the oceans controls the earth’s
temperature
the oceans control the earth’s temperature by
absorbing solar heat
water has the distinctive property of absorbing or utilizing
large amounts of heat without undergoing a great temperature change
the oceans can absorb or utilize great amount of heat without
undergoing a great temperature change
the levels of nutrient materials and dissolved salts in the marine biomes are
relatively constant
there are distinct ____ in the marine biomes
zones
zones in the marine biome
intertidal zone littoral zone pelagic zone photic zone aphotic zone
intertidal zone
low tides variation in temperature periods of dryness
populations of intertidal zones
algae sponges clams snails sea urchins starfish crabs
littoral zone
on continental shelf reaches depths of 600 ft extends several hundred miles from shores
population of littoral zone
algae crabs crustacea fish
pelagic zone
open seas
pelagic zone can be divided into
photic zone aphotic zone
photic zone
open sea sunlit layer depth of 250-600 ft
population of photic zone
plankton nekton
chief autotroph of photic zone
diatom (algae)
diatom
chief autotroph of photic zone algae
plankton
passively drifting masses of microscopic photosynthetic and heterotrophic organisms
nekton
active swimmers fish sharks whales
nekton feed on
nekton feed on plankton
aphotic zone
region beneath photic zone no sunlight
there is no _____ in the aphotic zone
photosynthesis
only _____ exist in the aphotic zone
heterotrophs
deep-sea organisms in the aphotic zone have adaptations enabling them to survive in
very cold water high pressures complete darkness
population of aphotic zone
nekton benthos
benthos
crawling and sessile organisms
scavengers and predators
occupy aphotic zone
the habitat of the aphotic zone is fiercely
competitive
intertidal, littoral, pelagic are (horizontal or vertical)
horizontal
photic, aphotic are (horizontal or vertical)
vertical
freshwater biomes
links between oceans and land
freshwater biomes contain
fresh water
examples of freshwater biomes
rivers lakes ponds marshes
rivers are routes by which ancient marine organisms
reached land and evolved terrestrial adaptations
many marine organisms failed to adapt to land and developed
adaptations for fresh water
some marine organisms developed adaptations for both ____ and _____
land and fresh water
factors affecting life in fresh water
temperature transparency depth of water available CO2 and O2 salt concentration
most important factor affecting life in fresh water
salt concentration
transparency
illumination due to suspended mud particles
fresh water biomes differ from salt water biomes in ___ basic ways
3
fresh water is (hypertonic or hypotonic)
hypotonic
hypotonic water creates a diffusion gradient resulting in
passage of water into the cell
fresh-water organisms have homeostatic mechanisms to maintain
water balance
homeostatic mechanisms of fresh-water organisms to maintain water balance by the
removal of excess water
examples of mechanisms to remove excess water (maintain water balance) - protozoa and fish
contractile vacuoles or protozoa excretory systems of fish
plant cells maintain water balance because they have
rigid cell walls that build up cell pressure
rigid cell walls build up pressure as
water flows in
rivers and streams, because of the strong swift currents, have selected for plants that have developed
root-like hold-fasts
the pressure built up by rigid cell walls as water flows in counteracts
gradient pressure
the ability of the pressure built up by the rigid cells walls to counteract the gradient pressure stops the
influx of water and establishes a water balance
strong swift currents exist in
rivers and streams
rivers and streams, because of the strong swift current, select for fish that have developed
strong muscles
fresh water biomes (except for very large lakes) are affected by
variations in climate and weather
temperature and fresh water bodies
temp varies considerably - may freeze up or dry up
in addition to freezing and drying up, this physical attribute of fresh water bodies is affected
mud from floors may be stirred up by storms
three major ways fresh-water biomes differ from salt water biomes
- strong swift currents of rivers and streams 2. temperature and climate changes of small fresh water bodies (no great lakes) 3. hypotonic environment (fresh water) vs. hypertonic environment (salt water)
