Ecology: A Human Approach - Professor Pool - Test 1 Vocabulary

What are living things made of?

Carbon, nitrogen, phosphorus, oxygen, and hydrogen

proton

an atom with a positive charge; weighs 1.007 AMU

neutron

an atom with a neutral charge; weighs 1.008 AMU

electron

an atom with a negative charge; weighs .00055 AMU

atomic number

the number of protons of an element

atomic mass

the number of protons + neutrons of an element

ion

a positively or negatively charged atom or group of atoms

isotope

one of several atomic forms of an element, with each form having a different number of neutrons

element

a substance that cannot be broken apart into other substances

atom

the smallest unit of matter with the properties of an element

cation

a positively charged ion

anion

a negatively charged ion

covalent bond

a bond that occurs when two atoms share electrons in their electron orbitals

molecule

two or more atoms connected by covalent bonds

compound

a substance that includes atoms of two or more different elements in a certain ratio

ionic bond

the attraction between a positive ion and a negative ion

hydrogen bond

a weak bond created by an attraction between a positive charge on a hydrogen atom and a negative charge on a nearby atom

acid

a substance that increases the concentration of hydrogen ions (H+) in a solution

base

a substance that reduces the concentration of hydrogen ions (H+) in a solution

pH

a measure of the hydrogen ion (H+) concentration of a solution; a measure of the acidity of a solution; scale runs from 0 to 14; values below 7 are acidic and values above 7 are basic

energy

the capacity to do work

kinetic energy

the energy an object has as a result of motion

potential energy

the energy in an object as a result of its position, condition, or composition

first law of thermodynamics

the principle stating that energy can be transferred or transformed, but it cannot be created or destroyed

second law of thermodynamics

the principle stating that in every energy transformation, the energy of the final state will always be less than the energy of the initial state

joule (J)

the energy used (or work done) by a force of 1 newton over a distance of 1 meter

calorie

a unit of energy equivalent to 4.184 J

BTU

the abbreviation for “British thermal unit”; a unit of energy equivalent to about 1,055 J of energy

watt-hour (Wh)

the power of 1 watt operating for 1 hour

ideal gas law

a physical law that expresses the following relationship: PV = nRT where P = pressure, n = the number of gas molecules in moles, R = a proportionality constant, and T = temperature

cell

the smallest structure that can carry out the essential functions of an organism

organism

an individual living thing

population

consists of a group of individual organisms of the same species that live in a particular geographic area at the same time

community

a group of different populations of organisms living close enough together to interact

ecosystem

the combination of all the living organisms in a given area and the physical environment where they live

autotrophs

an organism that is able to make their own organic compounds, usually by photosynthesis; ex: plants, algae, some microorganisms

heterotrophs

an organism that obtains organic compounds from other organisms; ex: animals, fungi, some microorganisms

photosynthesis

the process by which plants and some other organisms use sunlight to produce sugar from carbon dioxide and water

light reactions

the first stage of photosynthesis, involving the capture and temporary storage of light energy

Calvin cycle

the second stage of photosynthesis, during which sugars are produced using the energy previously captured in the light reactions

cellular respiration

the biochemical process responsible for the breakdown of organic compounds in cells

sustainability

the ability to carry out an activity indefinitely into the future

sustainable development

the ability to meet the needs of the present without compromising the ability of future generations to meet their own needs

renewable resources

a naturally occurring resource that is replenished on a human timescale; ex: sustainable forests

nonrenewable resources

a natural material that is available on the planet only in fixed amounts or that cannot be regenerated on a human timescale

scientific method

a process by which scientists construct an accurate and objective representation of natural phenomena

hypothesis

a testable explanation of physical phenomena

scientific theory

an explanation for an aspect of the natural world that has been extensively tested and supported under a wide range of conditions by a large number of scientists

observations

a careful measurement of some aspect of the natural world

experiments

a controlled study involving a deliberate change in some factor in a physical or biological system and the measurement of responses

statistics

a field of mathematics focused on the analysis and interpretation of data

model

in environmental science, a conceptual or quantitative representation of a set of processes that occur in nature

peer review

the process of examination of scientific work by external expert evaluators

pseudoscience

claims that are presented using scientific language but that lack the rigorous testing and evaluation associated with true science

positive feedback loop

a cycle that occurs when part of a system responds to a change in a way that accelerates or amplifies the change

negative feedback loop

a cycle that occurs when part of a system responds to a change in a way that slows the change

independent variable

a type of data with a value that does not depend on other data

dependent variable

a type of data with a value that changes in response to another variable

biodiversity

the variety and variability of living organisms in a specific area

gene

a hereditary unit consisting of a specific sequence of nucleotides

DNA

deoxyribonucleic acid; the molecule of inheritance composed of a long sequence of varying combinations of nucleotides

RNA

ribonucleic acid; a nucleic acid used as a messenger molecule that carries genetic information from DNA to the cellular machinery used in protein synthesis

trait

a physical characteristic of an organism

species

a group of organisms that can interbreed with each other under natural conditions and produce fertile offspring

taxonomy

the scientific discipline concerned with naming and classifying the diverse forms of life

genome

the collection of all genes in an organism

evolution

a process by which organisms develop and diversify from earlier forms through natural selection and associated population-level genetic change

theory

an explanation for an aspect of the natural world that has been extensively tested and supported under a wide range of conditions by a large number of scientists

genetic mutation

a change that occurs in the DNA sequence of a gene

adaptations

inherited characteristics in the structure or function of an organism that makes it better suited to a particular physical and/or biological setting

natural selection

a process in which organisms that are most well-adapted to an environment tend to survive and transmit their genes to future generations

gene flow

the movement of genes as the result of the immigration of individuals into a population

genetic drift

a random change in the genetic makeup of a population

speciation

the process by which one species separates into two or more species

genetic diversity

the variation of genes within a species

species diversity

the variety of species present in a specific location and the relative proportions of the species present

ecosystem diversity

the variation in ecosystems across a landscape

species richness

the number of species found in a certain area

prokaryotic cell

a cell without a central membrane-bound nucleus

archaea

the domain of single-celled organisms with prokaryotic cells but genetically distinct from bacteria

bacteria

the domain of single-celled organisms with prokaryotic cells but genetically distinct from achaea

eukaryotic cells

a cell with a central membrane-bound nucleus

background extinction rate

the average loss of species over geologic time; estimated to be around 0.1-1 extinctions per million species per year

mass extinction

a period of time in the geologic record when vast numbers of species disappeared quickly and permanently; usually tied to major events; there are 5 well documented cases over the past 500 million years

vulnerable species

a species likely to become endangered unless the threats to its survival and reproduction are reduced

endangered species

a species at high risk of becoming extinct

critically endangered species

a species at an extremely high risk of extinction and/or having undergone a population decline of more than 80% in three generations

endemic species

a species found in only one place or part of the world

biodiversity hotspots

a geographic location with exceptionally high species diversity and a large number of endemic species; ex: the Californian Floristic Province along the coast of California

causes of extinction

habitat loss, invasive species, pollution, overexploitation, climate change

ecosystem energy balance

the difference between the amount of energy that enters and leaves an ecosystem

transpiration

the form of evaporation in which water is transported from the land surface to the atmosphere through a living plant

gross primary production

(GPP); the total CO2 that is converted into organic carbon (C) by photosynthetic organisms over a specific period of time

autotrophic respiration

the conversion of organic carbon to CO2 during cellular respiration in photosynthetic organisms

net primary production

(NPP); a measure of the difference between the flow of carbon into photosynthetic reactions (GPP) and the flow back to the atmosphere (as CO2) from automatic respiration; a measure of the net accumulation or loss of carbon in plants

hetroptrophic respiration

the conversion of organic carbon to CO2 during cellular respiration in organisms that consume organic material as food

net ecosystem production

(NEP); the difference between NPP and heterotrophic respiration; a measure of the net accumulation or loss of carbon in an ecosystem

microorganism

an organism too small to be seen by a human eye

macroorganism

an organism that can be seen by the human eye

physical weathering

the breakdown of rock structure through mechanical processes