Ch. 1 & 2 Vocab Flashcards
the scientific study of life
biology
new properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases
emergent properties
a type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles
eukaryotic cell
a type of cell lacking a membrane-enclosed nucleus and membrane-enclose organelles
prokaryotic cell
a double-stranded, helical nucleic acid molecule, consisting of nucleotide monomers with a deoxyribose sugar and nitrogenous bases adenine, cytosine, guanine, and thymine; capable of being replicated and determining the inherited structure of a cell’s proteins
DNA
discrete units of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some cases)
genes
the genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its noncoding nucleic acid sequences
genome
a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics
natural selection
recorded observations
data
a type of logic in which generalizations are based on a large number of specific observations
inductive reasoning
a tentative answer to a well-framed question, narrower in scope than a theory and subject to testing
hypothesis
a type of logic in which specific results are predicted from a general premise
deductive reasoning
an experiment in which an experimental group is compared with a control group that varies only in the factor being tested
controlled experiment
an explanation that is broad in scope, generates new hypotheses, and is supported by a large body of evidence
theory
representations of a theory or process
models
the application of scientific knowledge for a specific purpose, often involving industry or commerce but also including uses in basic research
technology
any substance that cannot be broken down to any other substance by chemical reactions
element
a substance of two or more different elements combined in a fixed ratio
compound
elements indispensable for life but required in extremely minute amounts
trace elements
the smallest unit of matter that retains the properties of an element
atom
subatomic particles having no electrical charge (neutral) with a mass of 1.7 x 10^-24 g, found in the nucleus of an atom
neutrons
subatomic particles with a single positive electrical charge, with a mass of 1.7 x 10^-24g, found in the nucleus of an atom
protons
subatomic particles with a single negative electrical charge and a mass about 1/2000 that of a neutron or proton; move around the nucleus of an atom
electrons
the sum of the number of protons and neutrons in an atom’s nucleus
mass number
the number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol
atomic number
one of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass
isotopes
an isotope that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy
radioactive isotope
electrons in the outermost electron shell
valence electrons
the three-dimensional space where an electron is found 90% of the time
orbital
a type of strong chemical bond in which two atoms share one or more pairs of valence electrons
covalent bonds
a type of molecular notation in which the constituent atoms are joined by lines representing covalent bonds
structural formula
a type of molecular notation representing the quantity of constituent atoms, but not the nature of the bonds that join them
molecular formula
a covalent bond between atoms that differ in electronegativity; the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
polar covalent bond
a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
nonpolar covalent bond
starting material in a chemical reaction
reactants
material resulting from a chemical reaction
products
in a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products do not change with time
chemical equilibrium
two or more atoms held together by covalent bonds
molecule
descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in the genetic composition of a population from generation to generation
evolution
