Biology - Ecology Flashcards
what is the environment?
everything that is external to an organism and is necessary for its existence
what is included in the physical/abiotic environment?
climate, temp, light and water availability and topology
what is in the biotic environment?
all living things that directly or indirectly influence the life of the…includes relationships
levels of biological organization (small to big):
organism, population, community, ecosystem, biosphere
parts of an organism (big to small):
organ systems, organs, tissues, cells, molecules, atoms, subatomic particles
what is a species?
group of organisms capable of reproducing
what is a population?
species living together in a specific location
examples of a population?
dandelions in a lawn, flies in a barn, lions in a grassland
what is a community?
different plants and animal species interacting with each other in an environment
what is a biotic community?
only populations interacting and not the environment
what is a ecosystem?
biotic communities and the nonliving environments
a community typically includes what?
all 5 kingdoms
examples of communities:
lawn, sea, pond, forest
what is included in the biosphere?
all portions of planet that support life: atmosphere, lithosphere and hydrosphere
same changes occur when you change latitude and as you change altitude
true
what is the photic zone in water?
top layer through which light can penetrate; where all aquatic photosynthesis takes places
what kind of life can exist in the aphotic zone?
animal life
how much of the air is oxygen?
20% so terrestrial life does not struggle with getting oxygen
how do aquatic plants and animals get oxygen?
the small amount of oxygen dissolved in water
what is substratum?
soil and rock
what plants are most suitable for growth in acidic soil?
rhododendrons and pines
what determines the water-holding capacity of soil?
texture and clay content
willows require what kind of soil?
moist
what is a loam?
no contains high percentages of each type of soil
why is beach sand unable to sustain life?
no minerals (ex: nitrates and phosphates)
how is humus quantity determined?
amount of decaying plant and animal life in soil
what is a niche?
functional role of an organism in its ecosystem; it encompasses every aspect of its existence
what is a habitat?
physical place an organism lives
what are the 3 possible outcomes when more than one species is completing for one resource due to similar niches:
extinction; elimination in some places; evolve in divergent directions so they would have greater differences in their niches
how do chemosynthetic bacteria obtain energy?
from the oxidation of inorganic sulfur, iron, nitrogen compounds
what evolved as a result of the cellulose-containing plant tissues that herbivores eat?
long digestive tracts for more digestion SA, and crushing/grinding structures
since herbivores cannot digest most of what they consume, what lives in their digestive tracts?
symbiotic bacteria that can digest cellulose
why are herbivores for adept for defense than carnivores?
they are often prey
kinds of teeth in herbivores?
molars for grinding and incisors for cutting
teeth in carnivores?
pointed teeth and canine teeth for tearing flesh
example of omnivores:
humans (eat both plants and animals)
what is symbiosis?
symbionts live together in intimate (often permanent) association and may or may not benefit both
what is an obligatory symbiotic relationship?
one or both organisms cannot live without the other
what is commensalism?
+/0 …one is benefitted and the other is not impacted
what is mutualism?
+/+
examples of mutualism:
tick bird and rhinos; fungi and algae in lichens; nitrogen-fixing bacteria and legumes; protozoa and termites; intestinal bacteria and humans
what is parasitism (+/-)
exists when competition for food is most intense; bacteria, fungi and animals
what are ectoparasites?
parasites that have a sucker or clamp and cling to the exterior surface of the host
what are endoparasites?
parasites that live inside the host
the more dangerous the parasite….
the less likely the parasite is to survive
true or false: all viruses are parasites?
true.
examples of parasitism:
virus and host cell; disease bacteria and animals; disease fungi and animals; worms and animals
example of disease bacteria and animals:
diptheria, anthrax, TB
example of disease fungi and animals
ringworm on humans
example of worms and animals:
tapeworm and humans
how do predators influence their prey?
regulatory influence….they do not threat its survival
define saprophytes:
protists and fungi that decompose dead organic matter externally and then absorb the nutrients
examples of saprophytes:
mold, mushrooms, bacteria of decay and slime molds
what are scavengers?
animals that consume dead animals
examples of scavengers:
vulture and hyena and snapping turtle
example of disruptive forces within a species
competition
example of cohesive forces within species:
reproduction and protection
what kind of environment do saltwater fish live in? what does this mean?
hyperosmotic; they lose water and take in salt
how do saltwater fish compensate for living in a hyper osmotic environment?
they constantly drink and excrete salts from their gills
what kind of environment do freshwater fish live in? what does this cause?
hypo-osmotic; excessive water intake and salt loss
how do freshwater fish compensate for living in hypo-osmotic environment?
rarely drinking and absorbing salts; DILUTE urine
how to insects conserve water?
they excrete solid uric acid crystals
how do camels prevent desiccation?
fat layers where they are exposed to the sun
how do horned toads prevent desiccation?
thick/scaly skin to prevent water loss
what do non-desert plants have to conserve water?
waxy cuticles and stomata on lower leaf; they shed leaves in the winter
how to desert plants conserve water?
extensive roots, fleshy stems that store water and spiny leaves to limit water loss, thick cuticles and few stomata
how much total energy is given off as heat?
60%
are most animals and plants cold or warm blooded? what is this called?
cold-blooded; poikilothermic
the body temp of poikilotherms is…..to their surrounding
similar
as the temp rises, poikilotherms become…..active
more
mammals are birds are what kind of blooded?
warm-blooded; homeothermic
physical adaptations that mammals and birds have to slow down heat loss:
hair, fat and feathers
producers of the food chain:
autotrophic green plants and chemosynthetic bacteria
typical producer of a food chain:
wheat plant; capture the energy of the sun in C-H bonds
what are primary consumers?
animals that consume green plants (herbivores)
examples of primary consumers:
cows, grasshoppers and elephants
what are secondary consumers?
animals that consume primary consumers (carnivores)
examples of secondary consumers:
frogs, tigers, dragonflies
what do decomposers do?
metabolize the waste of organisms into nitrates and phosphates
the greater the number of pathways in a community food web, the more……
stable the community
what is the second law of thermodynamics?
every energy transfer involves the loss of energy
which level of the food pyramid has the most energy?
producers at the bottom because energy is lost at each feeding level
describe the trend of mass in the food pyramid:
a large mass of producers can support a smaller mass of organisms at higher levels
describe the pyramid of numbers in the food pyramid:
the greatest number of organisms are at the bad and the smallest number of organisms are at the top
in general, as the pyramid is ascended…..
there are fewer organisms, less mass and less energy
what 2 things change nitrogen into usable nitrates?
lightning and nitrogen-fixing bacteria
why does nitrogen need to be recovered and reused?
is is chemically inert and cannot be used by a lot of organism and there is a finite amount of nitrogen
plants absorb nitrates and synthesize:
plant proteins and nucleic acids
animals eat the plants and synthesize:
animal proteins
how is the nitrogen in the waste of plants and animals released?
bacteria of decay which convert the proteins to ammonia.
two fates of NH3:
nitrified to nitrites; or denitrified to release free nitrogen
what are the 4 kinds of bacteria in the nitrogen cycle?
decay, nitrifying, denitrifying and nitrogen fixing
what do nitrifying bacteria do?
convert ammonia to nitrites (NO2) and then to nitrates (NO3-)
what do denitrifying bacteria do?
convert nitrates to free nitrogen that can be taken up by nitrogen fixing bacteria in the roots of legumes
carbon cycle:
organic compounds in animals are ingested by animals and then found in animals and their waste; the bacteria of decay return CO2 to the air and then plants use this to create glucose
3 conditions for stability of an ecosystem
stable abiotic factors/stable biotic community; constant energy source; cycling of materials between the living system and its environment
what is ecological succession?
one biotic community replaces or succeeds another until a climax community is established
what is a sere?
community stage
what is a lichen?
association between algae and fungus that can live on a rocky surface
what does the type of climax community depend upon?
the abiotic factors like rainfall, soil, temperature, shade…
what is a biome?
a distinct community existing in a major climate area
what plants and animals are in a desert biome?
lizards, insects, cactus, sagebrush and mesquite plants that conserve water actively
how are grassland biomes characterized?
low rainfall (10-30 inches a year)
true or false: grasslands provide no shelter for herbivorous animals from carnivorous predators.
true. most animals in this biome have long legs and hooves
what characterizes tropical rain forest biomes?
high temperatures and torrential rains
what is climax community of rain forest?
vegetation that doesn’t shed leaves
what are epiphytes? where are they commonly found?
plants that grow on other plants like in the rain forest.
what inhabits the floor of the rain forest?
saprophytes
characteristics off temperate deciduous forest biome?
cold winters, warm summers and moderate rainfall
trees found in temperate deciduous forest biome?
breech, maple, oaks and willows
characteristics of temperate coniferous forest biome?
cold and dry
trees of temperate coniferous forest biomes?
fir, pine, spruce
where are temperate coniferous forests?
Canada and extreme north of US
what is a taiga biome?
less rainfall than temperate with long, cold winters
tree of the taiga biome?
spruce
chief animal inhabitant in the taiga biome?
moose
what is the tundra biome?
treeless, frozen plain between the taiga lands and northern ice sheets
what animals/plants are in the tundras?
polar bears, oxen, arctic hens, moss and lichens
what kind of areas are the most stable ecosystem?
aquatic biomes
two types of aquatic biomes?
marine and freshwater
marine biomes contain a constant amount of ….
nutrient materials and dissolved salts
what is the intertidal zone of the marine biome?
exposed at low tides and undergoes variations in temp and dryness.
what populations are in the intertidal zone?
algae, sponges, clams, snails, starfish and crabs
what is the littoral zone of the marine biome?
deep ocean off continental shelf
what populations are in the littoral zone?
fish, crustacea, algae and crabs
what is the pelagic zone?
open seas
what are the photic and aphasic apart of?
pelagic zone
what is the photic layer? what animals live here?
sunlit region (250-600 feet); plankton, nekton and diatom is the chief autotroph (algae); fish, sharks and whales feed on the plankton
what is the aphotic zone?
below the photic layer that receives no sunlight
what kind of organisms make up the aphotic zone?
heterotrophs
2 kinds of organisms in the competitive aphotic zone?
nekton (active swimmers) and benthos (crawling and sessile organisms)
what are examples of freshwater biomes?
lakes, pons, rivers and marshes that connect oceans and land
what is the tonicity of freshwater? what does this cause to happen to cells?
hypotonic; passage of water into the cell
how do plants in freshwater areas establish a water balance?
they have rigid cell walls that build up pressure (turgor) as water flows in; gradient stops.
what do the currents of freshwater biomes favor?
strong muscle plants and plants with holdfast roots
true or false: the temperature of freshwater bodies varies considerably.
true.
