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42 Cards in this Set

  • Front
  • Back
What are the two components of an organism's environment?
Abiotic - Physical environment
Biotic - Living environment
What are the levels of Biological Organization?
Organism - Individual unit of an ecological system
Species - Group of similar organisms capable of breeding
Population - Group of organisms of the same species living together in a given location
Communities - Consists of populations of different plants and animal species
Ecosystem - Includes communities and environment (biotic and abiotic)
Biosphere - All portions of planet that support life (atmosphere, lithosphere (rock and soil surface), hydrosphere (oceans))
What are photic and aphotic zones of the ocean?
Photic - Top layer where light can penetrate and photosynthesis can occur. Heterotrophic and autotrophic organisms exist here

Aphotic - Bottomw layer where no light can penetrate and organisms are only heteroptrophic
What is Humus Quantity?
The amount of decaying plant and animal life in the soil
What is the niche?
Defines functional role of an organism in its ecosystem

Niche different than habitat

Niche defines the range of living conditions that an organism can tolerate

No two species can occupy same niche
What are autotrophs?
Organisms that manufacture their own food
What are heterotrohps and what types are there?
Depend on autotrophs and other heterotrophs as food source

Herbivores, Carvnivores, Omnivores
What are herbivores?
Consume on plants or plant food

Have long digestive tracts to provide greater surface area and time for digestion

Symbiotic bacteria break that down cellulose inhabit the digestive tracts of herbivores

Herbivores are more adept to defense than carnivores because they are often prey
What are carnivores?
Only eat other animals

Possess shorter digestive tracts due to the easier digestibility of animal food
What are omnivores?
Animals which eat both plants and animals
What is symbiosis?
Intimate, often permanent, associations which may or may not benefit both participants

Some are obligatory, that is one cannot survive without the other
What are the three types of symbiosis?
What is commensalism?
One benefits: Other unaffected

Remora and Shark - Protection, food, dispersal

Barnacle and Whale - Food, dispersal
What is Mutualism?
Both organisms benefit

Tick Bird and Rhinoceros - Bird eats ticks, Rhino gets cleaned and warned of danger

Lichen (Fungus and an algae)

Nitrogen fixing bacteria and legumes - Legume provides nutrients for bacteria, and bacteria fixes nitrogen

Protozoa and Termites - Allows digestion of cellulose and gives home and food

Intestinal bacteria and humans - manufacture vitamin K, use excess food
What is parasitism?
One benefits:One gets hurt

Ectoparasites - Exterior to host
Endoparasites - live within host
What is saprophytism?
Protists and fungi that decompose dead organic matter externally and absorb the nutrients

mold, mushrooms, bacteria of decay and slime molds
What are scavengers?
Consume dead animals, have no adaptations for hunting and killing prey

Vulture or hyena

Snapping turtle is scavenger and a predator
What type of osmoregulation exists?
Saltwater fish live in hyperosmotic environment which causes them to lose water and take on salt, constantly drink water and secrete salt

Freshwater fish live in hypoosmotic environment which causes intake of excess water and excessive salt loss. Rarely drink, absorb salts, excrete dilute urine

Insects secrete uric acid crystals to conserve water
What are poikilothermic animals?
"Cold blooded"

Can not regulate temperature of body

Metabolism is linked to temperature of environment
What are homeothermic animals?
"Warm Blooded"

Mammals and Birds

Make use of heat produced

Also have adaptations like fat, hair, feathers

Constant internal temperature

Able to inhabit greater environments
What is the purpose of the nitrogen cycle?
Elemental Nitrogen is chemically inert and cannot be used by most organisms. Lightning and nitrogen-fixing bacteria change nitrogen into soluble nitrates and are easily absorbed by plants
What are the different steps of the nitrogen cycle?
Animals eat plants and synthesize animal proteins, create wastes, eventually die

Nitrogen locked up in waste and dead tissues is released by the action of bacteria of decay which convert the protein to ammonia

Two fates: Some is nitrified to nitrites by chemosynthetic bacteria and then to usable nitrates by nitrifying bacteria. The rest of the ammonia is denitrified (broken up) to release elemental Nitrogen to return to beginning of cycle
What is the basis of the carbon cycle?
Plants produce glucose via photosynthesis -> Animals eat plants to form structures characteristic of the species -> Part is used as fuel in respiration and CO2 is released -> Rest of organic carbon is released at death of organism by bacteria
What is a climax community?
Stable, living (biotic) part of the ecosystem described above in which populations exist in balance with each other and with the environment

Depends on abiotic factors

Climax community exists until some major climate or geographical change affects the populations with upset equilibrium
What is a sere?
Biological community that exists on the pathway to creating a climax community

Replacement with new seres stops when a climax community has been reached

Every sere is dominated by a dominant species that controls the other species present
How are land biomes characterized and named?
According to the climax vegetation of the region

Climax vegetation then determines the climax animal population
What is characteristic of the Desert Biome?
<10 in rain, concentrated in a few outbursts

Growing season restricted to few days following the outburst

Small plants and animals

Plants actively conserve water

Animals live in burrows

Few birds and mammals

Sahara in Africa, Gobi in Asia
What is characteristic of the Grassland Biome?
10-30 inches rainfall

No shelter for herbivores animals from predators

Animals have long legs and many are hoofed

Praires east of the Rockies, Steppes of the Ukraine, Pampas of Argentina
What is characteristic of the Tropical Rain Forest Biome?
High temps, torrential rain


Dense vegetation with no leaf shedding

Epiphytes (plants growing on other plants), vines grow here

Plants grow close together with hardly any sunlight reaching the floor

Saprophytes live on floor on dead matter

Central Africa, Central America, Amazon Basin, Southeast Asia
What is characteristic of the Temperate Deciduous Forest Biome?
Cold winters, warm summers, moderate rainfall

Beech, maple, oaks, willows shed their leaves during cold winter months

Deer, fox, woodchucks, squirrel

Northeast and Central-Eastern US, Central Europe
What is characteristic of the Temperate Coniferous Forest Biome?
Cold, dry

Fir, pine, spruce

Evolved water conservation such as needle-shaped leaves

Extreme northern part of US, Southern Canada
What is characteristic of the Taiga Biome?
Less rainfall than temperate forests

Long cold winters

Single coniferous tree - Spruce

Taiga forest floor contains moss and lichens

Moose, black bear, wolf, some birds

Northern parts of Canada, USSR
What is characteristic of the Tundra Biome?
Treeless, frozen plain

Between taiga lands and northern ice sheets

Very short summer and very short growing season

Lichens, moss, polar bears, musk oxen, arctic hens
What is characteristic of the Polar Biome?
Frozen area with no vegetation nor terrestrial animals

Any animals live near polar oceans
How do the terrestrial biomes compare with altitude?
As you move from equator to polar, same biomes as sea level to highest peaks
Where does 90% of the earths food and oxygen production occur?
In the water
What are the two major aquatic biomes?
Fresh water
How are aquatic biomes classified different than terrestrial?
Aquatic not based on plant life, plant life has very little impact on aquatic environment
What are the regions of marine biome from shore on out?
Intertidal Zone - Region exposed at low tides, experiences temp change, algae, sponges, clams, snails, sea urchins, starfish, crabs

Littoral Zone - Region on continental shelf wich contains ocean areas with depth up to 600 feet and extends hundreds of miles from shore, algae, crabs, crustacea, fish
Pelagic Zone - Typical of the open seas, divided into photic and aphotic zones
What is the photic zone?
Sunlit layer of open sea extending 250-500 ft in depth. Contains plankton, and nekton (active swimmers like fish, sharks or whales)

Chief autotroph is the diatom, an algae
What is the aphotic zone?
Region below photic zone, recieves no light

Only heterotrophs exist here

Contain nekton and benthos organisms (crawling and sessile)

Fiercely competitive environment
How do organisms deal with the difficulties of freshwater living?
Fresh water is hypotonic creating a diffusion gradient where water flows into cell

Cells have special mechanisms to remove excess water

Fish are strong to swim against current

Plants have strong holds to ground