Ecology Flashcards
Ecology
The study of the interactions between organisms and their environment
Two components of an organisms’s enviroment:
Physical (abiotic)
Living (biotic)
Physical environment includes:
climate, temperature, availability of light and water, and the local topology.
Biotic environment
All living things that directly or indirectly influence the life of the organism.
Organism
Individual unit of an ecological system.
Population
Group of organisms of the same species living together in a given location.
Species
Any group of similar organisms that are capable of reproducing with each other.
Community
Populations of different plants and animal species interacting with each other in a given encironment
Biotic environment
Only includes the population and not the physical environments
Ecosystem
Includes the community and the environment.
Biosphere
Includes all portions of the planet that support life- the atmosphere, the lithosphere (rock and soul surface) and the hydrosphere (oceans). RELATIVELY THIN LAYER
Photic zone
In water- the top layer through which light can penetrate. Where all of the photosynthesis takes place.
Aphotic zone
only animal life and other heterotrophic life exist
What is soil affected by?
Acidity
Texture of soil
Minerals (nitrates and phosphates) affect the type of vegetation that can be supported
Humus quantity is determined by the amount of decaying plant and animal life in soil.
Niche
Defines the functional role of an organism in its ecosystem.
Habitat
The latter is the physical place where an organism lives.
What does the niche describe?
What the organism eats, where and how it obtains its food, what climatic factors it can tolerate and which are optimal the nature of its parasites and predatos, where and how it reproduces and so on.
True or false: two organisms can occupy the same niche
FALSE
ORGANISMS occupying the same niche compete:
for food, water, light, oxygen space, minerals, and reproductive sites.
Why do herbivores have long digestive tracts?
This provides greater surface area and time for digestion.
Symbiotic bacteria of herbivores
Capable of digesting cellulose- inhabit the digestive tracts if herbivores.
Symbiosis
Close interrelationship of two different species.
what kind of organism if most adept at defense?
Herbivores because they are more often prey.
Obligatory symbiotic relationship:
One or both organisms cannot survive without the other.
Commensalism
When one organism is benefited by the association and the other is not affected.
Mututalism
Both organisms derive some benefit.
Parasitism
Parasite benefits at the expense of the host.
Ectoparasits
Use suckers or clamps
Endoparasites
Live within the host
All viruses:
parasites. Nonfunctional without the host
Disease bacteria and animals
Most bacteria are either chemosynthetic or saprophytic.
Saprophytic
Feed on decaying or dead matter
Disease fungi and animals
Most fungi are saprophytic
Worms and animals
Tapeworm. SUCCESSFUL parasites do not kill their host. The more dangerous the parasite, the less chance it will survive.
Predation includes both:
herbivores and carnivores
Saprophytism
Includes protists and fungi that decompose dead organic matter externally. Mold, mushrooms, bacteria of decay and slime molds
Scavengers
Are animals that consume that consume dead animals
Bacteria of decay may be considered scavengers
Vulture and hyena
What kind of environment do saltwater fish live in?
Hyperosmotic environment- lose water and take in salt. Drink constantly and excrete salt across their gills
What kind of environment do freshwater fish live in?
Hypoosmotic environment- intake of excess water and excessive salt loss. Seldom drink water, absorb salkts and excrete dilute urine.
Insects exctrete:
Solid uric acid crystals to converse water.
Cuticles are ___ and prevent
WAXY, which prevents water loss from plants
Why do leaves shed leaves in the winter?
To avoid water loss
Desert plants have___ to limit water loss
spiny leaves, extra thick cuticles and only few stomata and fleshy stems to store water in.
Poikilothermic
Cold blooded animals and plants, most of their heat energy escapes to the environment.
Body temperature close to that of their surroundings
Homeothermic
Warm blooded- mammals and birds. Make use of the heat produced as a consequence of respiration
How much heat produced from cellular respiration is transferred to ATP bonds?
only a fraction
60% of heat produced is given off as heat.
Types of consumers of the food chain:
Producers, primary consumers, secondary consumers, tertiary consumers and decomposers.
Producers are:
Autotrophic green plants and chemosynthetic bacteria- example :wheat plant
Primary consumers
Herbivores
Secondary consumers
Animals that consume the primary consumers- carnivoes
Tertiary consumers
Animals that feed on secondary consumers
Decomposers
Saprophytic organisms are included. Bacteria and fungi.
Food web
The food chain is not a simple chain but an intricate web because almost every species is consumed by one or more other species.
The greater # of pathways on the food web, the more ____ the commnity
STABLE
Pyramid of energy
Each member of a food chain uses some energy it obtains from its food for its own metabolism and loses some additional energy in the form of heat.
What contains the greatest amount of energy in the food chain
The producers at the bottom on the pyramid.
What contains the least amount of energy in the food pyramid?
The consumers at the top.
Pyramid of mass
Since energy is lost at each level, each level can support a smaller biomass.
Pyramid of numbers
Consumer organisms that are higher in the food chain are usually larger and heavier than those farther down.
In general, as you go up the pyramid, what happens?
Less energy content, less mass, and fewer organisms.
What is the material cycle?
Material is cycles and recycled between organisms and their environments, passing from inorganic forms to organic forms and them back to the inorganic forms
What the the nitrogen cycle?
An essential component of amino acids and nucleic acids, which are the building blocks for all living things.
Elemental nitrogen
Chemically inert, cannot be used by most organisms. Lighting and N-fixing bacteria make it usable into nitrates.
Nitrates:
Are absorbed by plants and synthesize specific animal proteins from the plant proteins. When animals and plants die, thye give off nitrogenous wastes
Nitrogen locked up in wastes
Is released by the action of the bacteria of decay, which convert the proteins into ammonia
Ammonica
1- Nitrified to nitrites by chemosynthetic bacteria and then to usable nitrates by nitrifying bacteria.
2. Rest is denitrified
Denitrified
Ammonia is broken down to release free nitrogen, which returns to the beginning of the cycle.
What are the four types of bacteria involved in the nitrogen cycle?
Decay, nitrifying, denitrifying, nitrogren-fixing.
The bacteria have no use for excretory ammonia, nitrites, nitrates, and nitrogen they produce. Essential for other living organisms.
Carbon cycle
Gaseous CO2 enters the living world when plants use it to produce glucose via photosynthesis
Carbon atom from CO2 are bonded to hydrogen and other carbon atoms to form glucose- the plants uses the glucose to make starch, proteins, and fat.
Animals eat plants and use the digested nutrients to form carbohydrates, fats and proteins.
Metabolically produced CO2 is released to the air. Rest of the organic carbon remains locked within an organism until its death at which time bacteria decay and return to CO2 air.
What does a stable ecosystem require?
Constant energy source, and a living system incorporating this energy into organic compounds.
Cycling
Materials between in the living system and its environment is critical.
Climax community
Stable, living part of the ecosystem
What happens once the equilibrium is upset?
New climax condition are produced and new communities will be established in the ecosystem.
Ecological succession
Orderly process by which one biotic community replaces or succeeds another climax community is established
Sere
Each community state- identified by the dominant species
Successive communities must be able to
Survive in the environment that lead to the demise of the community preceding it.
The evolutionary origin of plants and animals are:
traced to the seas
Biome
Each geographic region is inhabited by a distinct community called a biome.
How are land biomes characterized and named?
By the climax vegetation of the region
What does the climax vegetation of the region determine?
The climax animal population.
Desert biome
Only small plants and animals, which live in burrows
Grassland biome
Low rainfall. No shelter for herbivores from carnivores. Animals have long legs and hooves. Prairies, pampas and steppes
Tropical rainforest biome
Jungles. High temperatures and torrential rains. Dense growth of vegetation that does not shed its leaves.
Sunlight doesn’t each flood- which is inhabited by saprophytes living off dead organic material
Epiphytes
Plants growing on other plants
Temperate deciduous forest biome
Cold winters, warm summers, and moderate rainfall. Leaves shed during winter. Deer, fox, woodchuck and squirrel.
Temperate coniferous forest biome
Cold, dry, and inhabited by fir, pine, and spruce trees.
Taiga biome
Less rainfall than temperate forest, have long, cold winters and are inhabited by a single coniferous tree. Moose.
Tundra biome
Treeless, frozen plain. Short summer. Lichens, moss, polar bears, musk oxen , and artic hens
Polar
frozen no vegetation and terrestrial animals. Animals that do inhabit polar regions generally live near the polar oceans
As much as 90% of earth’s food and oxygen production happens in the:
water
True or false: plants control a lot of aquatic biomes.
FALSE
Two types of major aquatic biomes
marine and freshwater
Intertidal zone
Type of marine zone. Region exposed at low tides that undergoes variations in temperature and periods of dryness. Algae, sponges, clams snails, sea urchins, starfish, and crabs.
Littoral zone
Marine. Continental shelf that contains ocean area with depths up to 600 feet and extends several hundred miles from shores. Algae, crabs and some fish.
Pelagic zone
Region typical of the open seas and can be divided into photic and aphotic.
Photic zone
Sunlit layer. 250-600 feet. Plankton: passively drifting masses of microscopic photosynthetic and heterotrophic organisms (sharks, fish, whales) and nekton. DIATOM: algae
Aphotic zone
No sun. No photosynthesis. Only heterotrophs.
Nektons and benthos. Fiercely competitive.
Freshwater biomes
Rivers lakes ponds and marshes: links between ocean and land
What are factors affecting life in marine biomes?
Temperatre, transparency, depth of water, available CO2 and oxygen, and salt concentration
