1.1 What is Science?
Science – the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment
Observation – The process of noticing and describing events or processes in a careful orderly way
Inference – A logical interpretation based on prior knowledge and experience
Hypothesis – A possible explanation for a set of observations or possible answer to a scientific question
Controlled experiment – Experiment in which only one variable is changed
Independent variable – A factor in a controlled experiment that is deliberately changed
Dependent variable – A variable that is observed and that changes in response to the independent variable
Control group –A group in an experiment that is exposed to the same conditions as the experimental group except for one independent variable
Data – evidence or information obtained from observation
1.2 Science in Context
Theory – A well tested explanation that unifies a broad range of observations and hypotheses and enables scientists to make accurate predictions about new situations
Bias – A particular preference or point of view that is personal rather than scientific
1.3 Studying Life
Biology – Scientific study of life
DNA – Deoxyribonucleic Acid, a self-replicating material present in nearly all-living organisms as the main constituent of chromosomes It is the carrier of genetic information.
Stimulus – A signal to which an organism responds
Sexual Reproduction – A type of reproduction in which cells from two parents unite to form the first cell of a new organisms
Asexual Reproduction – The process of reproduction involving a single parent that results in offspring that are genetically identical to the parent
Homeostasis – Relatively constant internal physical and chemical conditions that an organism maintains
Metabolism – the chemical processes that occur within a living organism in order to maintain life
Biosphere – The part of the Earth in which life exists including land, water, air and atmosphere
3.1 What is Ecology?
Biosphere – The part of the Earth in which life exists including land, water, air and atmosphere
Species – A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding fertile offspring
Population – A community of animals, plants, or humans among whose members interbreeding occurs
Community – A group of interdependent organisms of different species growing or living together in a specified habitat
Ecology – The branch of biology that deals with the relations of organisms to
Ecosystem – A biological community of interacting organisms and their physical environment
Biome – A large naturally occurring community of flora and fauna occupying a major habitat
Biotic Factor – Living factors
Abiotic Factor – Nonliving factors
3.2 Energy, Producers and Consumers
Autotroph – An organisms that produce their own energy/ food through such methods as chemosynthesis or photosynthesis
Primary Producer – Autotrophs
Photosynthesis – The process by which plants and other autotrophs to capture light energy and use it to power chemical reactions that convert CO2 and water into oxygen and energy rich carbohydrates such as sugars and starches
Chemosynthesis – A process in which chemical energy is used to produce carbohydrates
Heterotroph – A consumer
Consumer – An organism that relies on other organisms for its energy and food supply, also called a heterotroph
Carnivore – An organism that obtains energy by eating animals
Herbivore – An organism that obtains energy by only eating plants
Scavenger – An animal that consumes the carcasses of other animals
Omnivore – An organism that obtains energy by eating both plants and animals
Decomposer – An organism that breaks down and obtains energy from dead organic matter
Detrivore – An organism that feeds on plant and animal remains and other dead matter
3.3 Energy Flow in Ecosystems
Food chain – A series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
Phytoplankton – Photosynthetic algae found near the surface of the ocean
Food web – A network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem
Zooplankton – A small free floating animal that form part of plankton
Trophic level – Each level or step in a food chain or web
Ecological pyramid – An illustration of relative amounts of energy or matter contained within each trophic level in a given food chain or web
Biomass – The total amount of living tissue within a given trophic level
3.4 Cycles of Matter
Biogeochemical cycle – The process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
Nutrient – A chemical substance that an organism needs to sustain life
Nitrogen Fixation – The process of converting nitrogen gas into nitrogen compounds that can absorb and use
Denitrification – A process by which bacteria convert nitrates into nitrogen gas
Limiting Nutrient – A single essential nutrient that limits productivity in an ecosystem
4.1 Climate
· Weather – day to day conditions of the atmosphere, including precipitation and temperature
· Climate – The average year to year conditions f temperature and precipitataion that occur in an area over a long period.
· Microclimate – environmental conditions within a small area that differs signifigantly from that of the surrounding area
· Greenhouse effect – process in which certain gases (carbon dioxide, methane and water vapor) trap sunlight energy in earth’s atmosphere as heat
4.2 Niches and Community Interactions
· Tolerance – the ability of an organism to survive and reproduce under circumstances that differ from their optimal conditions s
· Habitat – an area where an organism lives including the abiotic and biotic factors that affect it
· Niche – a full range of physical and biological conditions in which an organism lives and the way the organisms use those conditions
· Resource - any necessity of life such as food, water, nutrients, light and space
· Competitive exclusion principle – principle that states that no two species can occupy the same niche in the same habitat at the same time
· Predation – interaction in which one organism captures and feeds on the other organisms
· Herbivory - Interaction in which one animal, the herbivore feeds on producers
· Keystone species – a single species that is not usually abundant in a community yet it exerts strong control over the structure of the community
· Symbiosis – relationship in which two species live closely together
· Mutualism – a symbiotic relationship in which both species benefit from the relationship
· Parasitism – symbiotic relationship in which one organism lives on or inside the other organism and harms it
· Commensalism – the symbiotic relationship between organisms in which one organism benefits and the other is neither helped nor harmed
4.3 Succession
· Ecological succession – series of gradual changes that occur in a community following a disturbance
· Pioneer species – the first species to populate an area after a succession
· Primary succession – succession that occurs in an area in which no trace of a previous community is present
· Secondary succession – type of succession that occurs in an area that was only partially destroyed by disturbances
4.4 Biomes
· Canopy – Dense covering formed by the leafy tops of tall rain forest trees
· Understory – layer of a rain forest found underneath the canopy formed by shorter trees and vines
· Deciduous – Term used to refer to a type of tree that sheds its leaves during a particular season each year
· Taiga – a biome with long cold winters, and a few months od warm weather, dominated by coniferous evergreens also called a boreal forest
· Humus - material formed by decaying leaves and other organic matter
· Coniferous – Term used to refer to the trees that produce seed bearing cones and have thin needle shaped leaves
· Permafrost – layer of permanently frozen subsoil found in the tundra
4.5 Aquatic Ecosystems
· Photic zone – sunlight region near the surface of the water
· Aphotic zone – Dark layer of the oceans below the photic zone were sunlight does not penetrate
· Benthos – Organisms that live attached to or near the bottoms of bodies of water
· Plankton – microscopic organisms that live in aquatic environments
· Wetland – ecosystem in which water either covers the soil or is present at or near the surface for at least part of the year
· Estuary – a kind of wetland formed where a river meets the ocean
