Term | Definition |
Renewable Resources | Natural Resources that are replenished after use as long as the rate of consumption does not exceed the rate of replacement. |
Non-Renewable Resources | Natural resources that cannot easily be replaced; fossil fuels are an example. |
Ecosystem | The living and nonliving components of an environment, including the communities of organisms present and the physical and chemical environment with which they interact. |
Habitat | The physical environment where an organism lives and to which it is adapted. |
Biome | Large, geographically cohesive regions whose defining vegetation, its plant life, is determined principally by climate factors like temperature and rainfall. |
Aquatic: Marine | This biome covers about three-fourths of the earth and includes the oceans, coral reefs, and estuaries. |
Aquatic: Freshwater | A biome characterized by having low salt concentration. Freshwater biomes include ponds and lakes, rivers and streams, and wetlands. |
Tropical Forest | Tropical forests are biomes characterized by warm temperatures and sufficient rainfall to support the growth of trees. Tropical forests may be deciduous or evergreen, depending on the presence of a dry season. |
Temperate Forest | Characterized by moderate winters and rainfall. Trees are mostly evergreen or deciduous, dropping their leaves in winter. |
Grassland | A biome characterized by perennial grasses and other non-woody plants. In North America, the prairies are examples of grasslands. |
Desert | A biome characterized by extreme dryness. Cold deserts experience cold winters and hot summers, while hot deserts are uniformly warm throughout the year. |
Taiga | A biome characterized by evergreen trees, with long and cold winters and only short summers. |
Tundra | A biome that occurs in the Arctic and mountain regions. Characterized by low growing vegetation and a layer of permafrost (frozen all year long) very close to the surface of the soil. |
Keystone Species | Species on which other species depend, and whose removal has a dramatic impact on the community. |
Community | A group of interacting population of different species living together in the same area. |
Stamen | The male reproductive structure of a flower, made up of a filament and an anther. |
Pistil | The female reproductive structure of a flower, made up of a stigma, style, and ovary. |
Stigma | The sticky "landing pad" for pollen on the pistil. |
Style | The tube-like structure that leads from the stigma to the ovary. |
Food Chain | A linked series of feeding relationships in a community in which organisms further up the chain feed on the ones below. |
Food Web | A complex interconnection of feeding relationships in a community. |
Parasitism | A type of symbiosis, a close relationship between two species, in which one species clearly benefits, and one species clearly loses. Because it involves one species feeding on another, parasitism is also a form of predation. |
Symbiosis | A relationship is which two different organisms live together, often interdependently. |
Mutualism | A type of symbiotic relationship in which both members benefit; a "win-win" relationship. |
Commensalism | A type of symbiotic relationship in which one member benefits and the other is unharmed. |
Niche | The space, environmental conditions, and resources that a species needs in order to survive and reproduce. |
Competitive Exclusion Principle | The concept that when two species compete for resources in an identical niche, one is inevitably driven to extinction. |
Ecology | The study of the interactions between organisms and between organisms and their nonliving environment. |
Population | A group of organisms of the same species living and interacting in a particular area. |
Community | Interacting populations of different species in a defined habitat. |
Ecosystem | All the living organisms in an area and the nonliving components of the environment with which they interact. |
Distribution Pattern | The way the organisms are distributed in geographic space, which depends on resources and interactions with other members of the population. |
Random | Individuals are equally likely to be anywhere within the area. |
Clumped | High-density clumps are separated by area of low abundance. |
Uniform | Individuals maximize space between them by being uniformly spaced. |
Growth Rate | The difference between the birth rate and the death rate of a given population; also known as the rate of natural increase. |
Immigration | The movement of individuals into a population. |
Emigration | The movement of individuals out of a population. |
Exponential Growth | The unrestricted growth of a population increasing at a constant growth rate. |
Habitat | The physical environment where an organism lives and to which it is adapted. |
Logistic Growth | A pattern of growth that starts off fast and then levels off as the population reaches the carrying capacity of the environment. |
Carrying Capacity | The maximum population size that a given environment or habitat can support given its food supply and other natural resources. |
Population Density | The number or organisms per unit area. |
Density-Dependent Factors | A factor whose influence on population size and growth depends on the number and crowding of individuals in the population (for example, predation). |
Biotic | Refers to the living components of an environment. |
Density-Independent Factors | A factor that can influence population size and growth regardless of the numbers and crowding within a population (for example, weather). |
Abiotic | Refers to the nonliving components of an environment, such as temperature and precipitation. |
Bryophytes
Example: Cat's tail moss | Nonvascular, so can't move water throughout their bodies
Small plants living in damp environments
Nonflowering; no seeds
Reproduction relies on water |
Ferns
Example: Sword Fern | Vascular, so can live in drier environments and move water throughout their bodies
Nonflowering; no seeds
Reproduction relies on water and involves spores |
Gymnosperms
Example: Douglas fir | Vascular, so cell wall of vascular cells support plant body to great heights
Seeds are "exposed" (typically held in cones) |
Angiosperms
Example: Big-Leaf maple | Vascular, so cell walls of vascular cells support plant body to great heights
Flowers are important in reproduction
Seeds are contained within fruit |
Bryophyte | A nonvascular plant that does not produce seeds. |
Vascular Plant | A plant with tissues that transport water and nutrients through the plant body. |
Sponges
E.g., Sea Sponge | No organized tissues
No Symmetry |
Cnidarians
E.g., Jellyfish | Radial Symmetry
Aquatic and marine habitat |
Flatworms
E.g., Flatworms | Simplest animal with bilateral symmetry |
Mollusks
E.g., Clam | Soft body
Single, hard outer shell |
Annelids
E.g., Earthworm | Long segmented body |
Nematodes
E.g., Roundworm | Long un-segmented body |
Arthropods
E.g., Insect | Exoskeleton
Segmented body
Jointed legs |
Echinoderms
E.g., Starfish | Endoskeleton
Spiny outer skin |
Chordates
E.g., Dog | Vertebrates have a backbone and spinal chord |
Fungus (Plural: Fungi) | A unicellular or multicellular eukaryotic organism that obtains nutrients by secreting digestive enzymes onto organic matter and absorbing the digested product. |
Decomposer | An organism such as a fungus or bacterium that digests and used the organic molecules in dead organisms as sources of nutrients and energy. |
Hypha (Plural: Hyphae) | A long, threadlike structure through which fungi absorb nutrients. |
Mycelium (Plural: Mycelia) | A spreading mass of interwoven hyphae that forms the often subterranean body of multicellular fungi. |
Protist | A eukaryote that cannot be classified as a plant, animal, or fungus; usually unicellular. |
Alga (Plural: Algae) | A uni- or multicellular photosynthetic protist. |
Prokaryote | A usually unicellular organism whose cell lacks internal membrane-bound organelles and whose DNA is not contained within a nucleus. |
Bacteria | One of the two domains of prokaryotic life; the other is Archaea. |
Flagella (Singular: Flagellum) | Whip-like appendages extending from the surface of some bacteria, used in movement of the cell. |
Pili (Singular: Pilus) | Short, hair-like appendages extending from the surface of some bacteria, used to adhere to surfaces. |
Capsule | A sticky coating surrounding some bacterial cells that adheres to surfaces. |
Adaptive Radiation | The spreading and diversification of organisms that occur when they colonize a new habitat. |
Punctuated Equilibrium | Periodic bursts of species change as a result of sudden environmental change. |
Biogeography | The study of how organisms are distributed in geographical space. |
Plate Tectonics | The movement of Earth's upper mantle and crust, which influences the geographical distribution of landmasses and organisms. |
Convergent Evolution | The process by which organisms that are not closely related evolve similar adaptations as a result of independent episodes of natural selection. Ex. Starfish |
Taxonomy | The process of identifying, naming, and classifying organisms on the basis of shared traits. |
Domain | The highest category in the modern system of classification; there are three domains, Bacteria, Archaea, and Eukarya. |
Descent with Modification | Darwin's term for evolution, combining the ideas that all living things are related and that organisms have changed over time. |
Fossils | The preserved remains of impressions of once-living organisms. |
Radiometric Dating | The use of radioactive isotopes as a measure for determining the age of a rock or fossil. |
Relative Dating | Determining the age of a fossil from its position relative to layers of rock or fossils of known age. |
Binary Fission | A type of asexual reproduction in which one parental cell divides into two. |
Fitness | The relative ability of an organism to survive and reproduce in a particular environment. |
Directional Selection | A type of natural selection in which organisms with phenotypes at one end of a spectrum are favored by the environment. |
Stabilizing Selection | A type of natural selection in which organisms near the middle of the phenotypic range of variation are favored by the environment. |
Diversifying Selection | A type of natural selection in which organisms with phenotypes at both extremes of the phenotypic range are favored by the environment. |