Ecology Flashcards
Ecology
the study of the interactions between organisms and their environment
Abiotic Environment
- the physical or nonliving environment
- includes climate, temperature, availability of light and water, and the local topology
Biotic Environment
the living environment
Organism
the individual unit of an ecological system, but the organism itself is composed of smaller units
Organs
- make up the organ system
- formed from tissues, tissues from cells, cells from many different molecules, molecules from atoms, and atoms from subatomic particles
Species
any group of similar organisms that are capable of producing fertile offspring
Population
a group of organisms of the same species living together in the same location
Community
- consists of populations of different plants and animal species interacting with each other in a given environment
- contains populations from all five kingdoms (monera, protists, plants, fungi, and animals)
Ecosystem
includes the community and the environment
Biosphere
includes all portions of the planet that support life: the atmosphere, the lithosphere, and the hydrosphere
Water
the major component of the internal environment of all living things
Temperature
must be maintained at an optimal level
Sunlight
the ultimate source of energy for all organisms
Photic Zone
the top layer of water through which light can penetrate, is where all aquatic photosynthetic activity takes place
Aphotic Zone
only animal and other heterotrophic life exist
Soil acidity/pH
may determine what types of plants grow in what types of soil
Texture of Soil
determine the water-holding capacity of the soil
Loams
contain high percentages of each type of soil
Minerals
affect the type of vegetation that can be supported
Humus
determined by the amount of decaying plant and animal life in the soil
Niche
- defines the functional role of an organism in its ecosystem
- describes what the organism eat, where and how it obtains its food, what climactic factors it can tolerate and which are optimal, the nature of its parasites and predators, where and how it produces, etc.
- no two species can ever occupy the same niche in the same location
Habitat
the physical place where an organism lies
Autotrophs
organisms that manufacture their own food
Heterotrophs
cannot synthesize their own food and must depend upon autotrophs or other heterotrophs in the ecosystem to obtain food and energy
Herbivores
consume only plants or plant foods
Symbiotic Bacteria
capable of digesting cellulose inhabit the digestive tracts of herbivores and allow the breakdown and utilization of cellulose
Carnivores
animals that eat only other animals
Omnivores
eat both plants and animals
Symbiosis
live together in an intimate, often permanent association, which may or may not be beneficial to both participants
Obligatory
one or both organisms cannot survive without the other
Commensalism (+/0)
-one organism is benefited by the association, and the other is not affected
Mutualism (+/+)
-a symbiotic relationship from which both organisms derive some benefit
Parasitism (+/-)
-a parasite benefits at the expense of the host
Predation
free-living organisms that feed on other living organisms
Saphrophytism
include those protists and fungi that decompose dead organism matter externally and absorb the nutrients
Scavengers
animals that consume dead animals
Osmoregulation
maintaining internal osmolarity and conserving water
Poikilothermic
cold-blooded animals and plants
Homeothermic
warm-blooded animals and plants
Food Chain
a single chain showing the transfer of energy
Producers
utilize the energy of the sun and simple raw materials to manufacture carbohydrates, proteins, and lipids
Primary consumers
animals that consume green plants (ex: cows, grassphoppers, and elephants)
Secondary Consumers
animals that consume the primary consumers (frogs, tigers, and dragonflies)
Tertiary Consumers
animals that feed on secondary consumers (carnivores)
Decomposers
include saprophytic organisms and organisms of decay, which include bacteria and fungi
Food Web
- an intricate collection of interconnected food chains
- the greater the number of pathways in a community food web, the more stable the community
Food Pyramids
-energy transfer involves a loss of energy
Pyramid of Energy
- each member of a food chain utilizes some of the energy it obtains from its food for its own metabolism and loses some additional energy in the form of heat
- the producers at the base of the pyramid contains the greatest amount of energy
Pyramid of Mass
-each level of the pyramid of energy can support a successively smaller biomass
Pyramid of Numbers
-consumer organisms that are highest in the food chain are usually larger and heavier than those further down
Material Cycles
-inorganic forms to organic forms and then back to the inorganic forms
Nitrogen Cycle
- an essential component of amino acids and nucleic acids, which are the building blocks of all living things
- four kinds of bacteria are involved in this cycle: decay, nitrifying, denitrifying, and nitrogen fixing
Carbon cycle
- gaseous carbon enters the living world when plants produce glucose via photosynthesis
- the metabolically produced carbon is released into the air
Conditions for Stability in an Ecosystem
- Relatively stable physical environment (abiotic factors) and a relatively stable biotic community
- Constant energy source and a living system incorporating this energy into organic compounds
- Cycling of materials between the living system and its environment is critical for a stable ecosystem
Ecological Succession
-the orderly process by which one biotic community replaces or succeeds another until a climax community is established
Climax Community
the stable, living (biotic) part of an ecosystem
Desert Biome
receive fewer than ten inches of rain each year
Grassland Biome
low rainfall, provide no shelter for herbivorous mammals
Rainforest Biome
aka jungles, trees grow close together, sunlight hardly reaches the forest floor
Temperate Deciduous Forest Biome
have cold winters, warm summers, and moderate rainfall
Temperature Coniferous Forest Biome
forests are cold, dry, inhabited mainly by trees that do not lose their leaves
Taiga Biome
receives less rainfall than temperate forests, have long cold winters
Tundra Biome
treeless, frozen plain found between the taiga and the northern ice sheets
Polar Region
surround the polar ice caps and are frozen areas with no vegetation and few terristrial animals
Intertidal zone
the region exposed at low tides that undergoes variations in temperature and periods of dryness
Neritic zone
the region on the continental shelf that contains ocean with depths up to 600 ft and extends several hundred miles from the shore
Pelagic Zone
typical of the open seas, this can be divided into phobic and aphotic zones
Photic Zone
the sunlit layer of the open sea extending a depth of 250-600ft
Aphotic Zone
the region beneath the photic zone that receives no sunlight
