Life Science Chapter 1,2,3,4,6,7

Terms	Definitions
Species	group of similar organisms that can mate with each other and produce fertile offspring
Fossil	preserved remains or traces of an organism that lived in the past
Adaptation	trait that helps an organism survive and reproduce (ex. beak shape)
Evolution	gradual change in a species over time
Scientific theory	well-tested concept that explains a wide range of observations
Natural selection	the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species
Variation	any difference between individuals of the same species
Homologous structures	similar structures that related species have inherited from a common ancestor
Branching tree	diagram that shows how scientists think different groups of organisms are related
Petrified fossil	Minerals replace the remains, changing them into rock
Mold	hollow space in sediment in the shape of an organism or part of an organism
Cast	mold may become filled with hardened minerals and a cast is a copy of the shape of the organism that made the mold
Relative dating	can help scientists determine whether one fossil is older than another, but does not tell actual age
Radioactive dating	allows scientists to determine actual age of fossils
Radioactive element	unstable elements that decay into different elements
Half-life	the time it takes for half of the atoms in a sample to decay
Fossil record	millions of fossils that scientists have collected
Extinct	no members of that species are still alive
Gradualism	theory that proposes that evolution occurs slowly but steadily
Punctuated equilibria	theory that proposes that species evolve quickly during relatively short periods
Cell	basic unit of structure and function in living things
Cell theory	theory that states that all living things are made of cells, cells are the smallest units of life, and cells can only come from other living cells
Macromolecule	large molecules made from smaller molecules joined together
Carbohydrate	energy storage molecules made of carbon, hydrogen, and oxygen
Nucleic acids	information containing macromolecules found in the nucleus of a cell
Proteins	macromolecules made from amino acids; found in membranes and many other cell structures
Lipids	energy storage macromolecules which do not dissolve in water
Nucleotides	long chains of molecules which combine in a specific order to make nucleic acids
Amino acids	building blocks of proteins
DNA	(deoxyribonucleic acid) molecule found in the nucleus which contains instructions for all things needed for life
RNA	(ribonucleic acid) gets information from DNA to make proteins
Homeostasis	ability to maintain stable internal conditions in the cell
active transport	energy-requiring process in which transport protiens bind with particles and move them through a cell membrane.
diffusion	a type of passive transport in cells in which molecules move from areas where there are more of them to areas where there are fewer of them.
nothing	process by which a cell takes in a substance by surrounding it with the cell membrane.
enzyme	a type of protien that regulates nearly all chemical reactions in cells; a type of protien that speeds up chemical reactions in the body without being changed or use up itself.
equilibrium	occurs when molecules of one substance are spread evenly throughout the other substance.
type "easy going"	easy going
fermentation	process by which oxygen-lacking cells and some one-celled organisms release small amounts of energy from glucose molecules and produce waste such as alcohol, carbon dioxide, and lactic acid.
inorganic compound	compound, such as H20, that is made form elements other than carbon and whose atoms usually can be arranged in only one structure.
metabolism	the total of all chemical reactions in an organism.
mixture	a combination of substances in which the individual susbtances do not change or combine chemically but instead retain their own individual properties; can be gases, solids, liquids, or any combination of them.
organic compounds	compounds that always contain hydrogen and carbon; carbohydrate, lipids, protiens, and nucleic acids are these and are found in living things.
osmosis	a type of passive transport that occurs when water diffuses through a cell membrane.
passive transport	movement of substances through a cell membrane without the use of cellular energy; includes diffusion, osmosis, and facilitated diffusion.
photosynthesis	process by which plants and many other producers use light energy to produce a simple sugar from carbon dioxide and water and give off oxygen.
respiration	process by which producers and consumers release stored energy from food molecules; series of chemical reactions used to release energy stored in food molecules.
organisms	living things
cell	the basic unit of structure and function in an organism
unicellular	single-celled organisms
multicellular	organism of many cells
stimulus	a change in an organism's surroundings
response	an action or change in behavior
development	the process of change that occurs during an organism's life
spontaneous generation	mistaken idea that living things can arise from nonliving things
autotrophs	organisms that make their own food
heterotrophs	organisms that can NOT make their own food
homeostasis	maintenance of stable internal conditions
classification	the process of grouping things based on their similarities
taxonomy	scientific study of how living things are classified
binomial nomenclature	naming of organisms system that Linnaeus used
genus	classification grouping that contains similar, closely related organisms
species	a group of similar organisms that can mate with each other and produce offspring
prokaryote	organisms whose cells lack a nucleus
nucleus	a dense area in a cell that contains the nucleic acids-the chemical instructions that direct the cell's activities
eukaryotes	organisms with cells that have a nucleus
Science	A way of learning about the natural world
Observing	The process of using one or more of your senses to gather info
Quantitative Observation	An observation that deals with a number or amount
Qualitative Observation	An observation that deals with characteristics
Inferring	An interpretation based on observations and prior knowledge
Predicting	The process of forecasting what will happen based on past experiences
Classifying	The process of grouping things based on their similarties
Making Models	The process of creating representations
Life Science	The study of living things
Scientific Inquiry	Propose explanations based on evidence they gather
Hypothesis	A possible explanation for a set of observations
Variable	A factor in an experiment that can change
Responding Variable	The factor that changes as a result of change
Operational Defination	A statement that describes how to measure a certain variable
Data	Facts, Figures, and other evidence gathered through observations
Communicating	The process of sharing ideas with others through writing and speaking
Technology	How people modify the world around them to meet their needs
Engineer	A person who is trained to use both technological and scientific knowledge
Manipulated Variable	The one factor that a scientist changes during an experiment
Controlled Experiment	An experiment in which only the one variable is manipulated at a time
Cell	basic unit of all living things
Cell membrane	thin, flexible barrier around a cell; regulates what enters and leaves the cell
Cytoplasm	a jellylike fluid inside the cell in which the organelles are suspended
Cell wall	strong wall outside a plant cell's cell membrane that protects the cell and maintains its shape
Organelle	a tiny cell structure that carries out a specific function within the cell
Nucleus	organelle that controls all the activities of a cell and contains hereditary material made of proteins and DNA
Chloroplast	a structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food
Mitochondrion	bean shaped organelle that releases energy from stored food molecules which supplies energy for the cell
Ribosome	an organelle that is resposible for making proteins.
Endoplasmic reticulum	a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.
Golgi body	A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell.
Tissue	group of similar cells that perform a particular function
type ":)"	:)
Organ system	group of organs that work together to perform a specific function
Organism	Any living thing
Mitosis	cell division in which the nucleus divides into nuclei containing the same number of chromosomes
Meiosis	A process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells
Chromosome	a structure in the nucleus that contains hereditary material
Vacuole	an organelle that stores food, water, and other materials needed by the cell
Multicellular	organisms composed of many cells
Unicellular	a type of organism that is made up of a single cell