honors biology 9 semester 1 vocab (chapters 1-9) final

science

organized way of gathering and analyzing evidence about the natural world

observation

process of noticing and describing events or processes in a careful, orderly way

inference

A logical interpretation based on prior knowledge and experience.

hypothesis

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

factor in a controlled experiment that is deliberately changed; also called manipulated variable

dependent variable

the variable that is observed and that changes in response to the independent variable; also called the responding variable

data

evidence; information gathered from observations

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

biology

the scientific study of life

DNA

genetic material that organisms inherit from their parents

stimulus

a signal to which an organism responds

metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

biosphere

the part of Earth in which life exists, including land, water, and air or atmosphere

atom

the basic unit of matter

nucleus

the center of an atom, which contains the protons and neutrons; a structure that contains the cell's genetic material in the form of DNA

electron

a negatively charged particle; located in the space surrounding the nucleus

element

a pure substance that consists entirely of one type of atom

isotope

one of several forms of a single element, each of which contains the same number of protons but different numbers of neutrons

compound

a substance formed by the chemical combination of two or more elements in definite proportions

ionic bond

a chemical bond formed when one or more electrons are transferred from one atom to another

covalent bond

a type of bond between atoms in which the electrons are shared

control group

group in an experiment that is exposed to the same conditions as the experimental group except for one independent variable

molecule

the smallest unit of most compounds that displays all the properties of that compound

cohesion

the attraction between molecules of the same substance

adhesion

the force of attraction between different kinds of molecules

solution

a type of mixture in which all the components are evenly distributed

suspension

a mixture of water and nondissolved material

acid

a compound that releases +hydrogen ions (H ) in solution; a solution with a pH of less than 7

base

a compound that releases -hydroxide ions (OH ) in solution; a solution with a pH of more than 7

buffer

a compound that prevents sharp, sudden changes in pH

carbohydrate

a compound made up of carbon, hydrogen, and oxygen atoms; a type of nutrient that is the main source of energy for the body

lipid

a macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

nucleic acid

a macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

protein

a macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

amino acid

a compound with an amino group on one end and a carboxyl group on the other end

chemical reaction

the process that changes, or transforms, one set of chemicals into another set of chemicals

activation energy

the energy that is needed to get a reaction started

catalyst

a substance that speeds up the rate of a chemical reaction

enzyme

a protein catalyst that speeds up the rate of specific biological reactions

ecology

the scientific study of interactions among organisms and between organisms and their environment

population

a group of individuals of the same species that live in the same area

community

a group of different populations that live together in a defined area

ecosystem

all the organisms that live in a place, together with their physical environment

biome

a group of ecosystems that share similar climates and typical organisms

biotic factor

any living part of the environment with which an organism might interact

abiotic factor

a physical, or nonliving, factor that shapes an ecosystem

autotroph

an organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer

primary producer

the first producer of energy-rich compounds that are later used by other organisms

heterotroph

an organism that obtains food by consuming other living things; also called a consumer

consumer

an organism that relies on other organisms for its energy and food supply; also called a heterotroph

food chain

a series of steps in an ecosystem in which organisms transfer energy by eating and being eaten

food web

a network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

trophic level

each step in a food chain or food web

ecological pyramid

an illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web

biomass

the total amount of living tissue within a given trophic level

biogeochemical cycle

a 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

nitrogen fixation

the process of converting nitrogen gas into nitrogen compounds that plants can absorb and use

denitrification

the process by which soil bacteria convert nitrates into nitrogen gas

climate

the average year-to-year conditions of temperature and precipitation in an area over a long period of time

microclimate

environmental conditions within as mall area that differ significantly from the climate of the surrounding area

greenhouse effect

the process in which certain gases(carbon dioxide, methane, and water vapor) trap sunlight energy in Earth's atmosphere as heat

habitat

an area where an organism lives, including the biotic and abiotic factors that affect it

niche

the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions

resource

any necessity of life, such as water, nutrients, light, food, or space

predation

an interaction in which one animal (the predator) captures and feeds on another animal (the prey)

herbivory

an interaction in which one animal (the herbivore) feeds on producers (such as plants)

symbiosis

a relationship in which two species live closely together

mutualism

the symbiotic relationship in which both species benefit from the relationship

parasitism

the symbiotic relationship in which one organism lives on or inside another organism and harms it

commensalism

the symbiotic relationship in which one organisms benefits and the other is neither helped nor harmed

ecological succession

a series of gradual changes that occur in a community following a disturbance

primary succession

succession that occurs in an area in which no trace of a previous community is present

pioneer species

the first species to populate an area during succession

secondary succession

a type of succession that occurs in an area that was only partially destroyed by disturbances

canopy

a dense covering formed by the leafy tops of tall rain forest trees

understory

the layer in a rain forest found underneath the canopy formed by shorter trees and vines

humus

material formed from decaying leaves and other organic matter

taiga

a biome with long cold winters and a few months of warm weather; dominated by coniferous evergreens; also called boreal forest

permafrost

a layer of permanently frozen subsoil found in the tundra

benthos

organisms that live attached to or near the bottom of lakes, streams, or oceans

plankton

typically small organisms that drift in, and may swim through, aquatic environments; includes both phytoplankton and zooplankton

wetland

an 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

age structure

the numbers of males and females in different age groups of a population

immigration

the movement of individuals into an area occupied by an existing population

emigration

the movement of individuals out of an area

exponential growth

a growth pattern in which the individuals in a population reproduce at a constant rate

logistic growth

a growth pattern in which a population's growth rate slows or stops, following a period of exponential growth

carrying capacity

the largest number of individuals of a population that a given environment can support

limiting factor

a factor that causes the growth of a population to decrease

density-dependent limiting factor

a limiting factor that depends on population size

demography

the scientific study of human populations

demographic transition

a change in a population from high birthrates and death rates to low birthrates and death rates

monoculture

a farming strategy of planting a single, highly productive crop, year after year

renewable resource

a resource that can be produced or replaced by healthy ecosystem functions

nonrenewable resource

a resource that cannot be replenished by natural processes within a reasonable amount of time

desertification

lower land productivity caused by overfarming, overgrazing, seasonal drought, and climate change

deforestation

the destruction of forests