allele
alternate forms of a gene or DNA sequence, which occur on either of two homologous chromosomes in a diploid organism
codominance
an inheritance relationship in which neither of two alleles of the same gene totally mask the other
dominance
a characteristic in which an allele that expresses its phenotype even in the presence of a recessive allele
genotype
the structure of DNA that determines the expression of a trait
incomplete dominance
a condition where a heterozygous off- spring has a phenotype that is distinctly different from, and intermediate to, the parental phenotypes
independent assortment
the law stating that pairs of genes separate independently of one another in meiosis
molecular genetics
the branch of genetics that deals with the expression of genes by studying the DNA sequences of chromosomes
multiple allels
three or more alleles of the same gene that code for a single trait
phenotype
he observable characteristics of an organism, the expression of gene alleles (genotype) as an observable physical or biochemical trait
punnett square
a type of grid used to show the gametes of each parent and their possible offspring; a type of grid that can indicate all the possible
recessive gene
characterized as having a phenotype expressed only when both copies of the gene are mutated or missing
applied science
the practical use of scientific information to improve human life
natural selection
the differential survival and reproduction of organisms with genetic characteristics that enable them to better utilize environmental resources
mutation
an alteration in DNA structure or sequence of a gene
variation
differences in the frequency of genes and traits among individual organisms within a population
biological evolution
change in allele frequency of a species or population over time
artificial selection
breeding organisms by humans for specific phenotypic characteristics
relative dating
a method of determining the age of fossils by comparing them to other fossils in different layers of rock
radioactive dating
a method of determining the age of an object by measuring the amount of a specific radioactive isotope it contains
mass extinction
one of the brief periods of time during which large numbers of species disappeared
antibiotic resistance
the ability of a microorganism to produce a protein that disables an antibiotic or prevents transport of the antibiotic into the cell
theory
a well tested explanation of natural events
evolution
the long-term process through which a population of organisms accumulates genetic changes that enable its members to successfully adapt to environmental conditions and to better exploit food resources
domain
taxonomic category that includes one or more kingdom
eukaryote
an organism whose cells possess a nucleus and other membrane-bound vesicles, including all members of the protist, fungi, plant and animal kingdoms; and excluding viruses, bacteria, and blue-green algae
prokaryote
a bacterial cell lacking a true nucleus; its DNA is usually in one long strand
autotroph
an organism that uses energy to synthesize organic molecules from inorganic substances
heterotroph
an organism that obtains organic food molecules by eating organisms or their by-products
pathogen
organism which can cause disease in another organism
parasitism
the close association of two or more dissimilar organisms where the association is harmful to at least one
sexual reproduction
process by which cells from two different parents unite to produce the first cell of a new organism
asexual reproduction
process by which a single parent reproduces by itself
vascular plants
a plant that has phloem and xylem
nonvascular plants
a plant that lacks vascular tissue and true roots, stems, and leaves
photosynthesis
the process by which light energy is converted to chemical energy stored in organic molecules
cellular respiration
the process by which cells generate ATP through a series of redox (chemical) reactions
biodiversity
the wide diversity and interrelatedness of earth organisms based on genetic and environmental factors
aerobic respiration
type of respiration that uses oxygen
anaerobic respiration
type of respiration that does not use oxygen
ecology
the study of the interactions of organisms with their environment and with each other
biotic factor
a living component of an ecosystem
abiotic factor
any non-living component of an ecosystem (e.g., sunlight, air, water, soil)
biosphere
the area on and around Earth where life exists
symbiosis
the close association of two or more dissimilar organisms where both receive an advantage from the association
commensalism
symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed
mutualism
a form of symbiosis in which both organisms benefit from living together
energy pyramid
summarizes interactions of matter and energy at each trophic level
ecosystem
the organisms in a plant population and the biotic and abiotic factors which impact on them
aero-
air
bacter-
bacterium, stick, club
carn-
meat, flesh
chlor-
green
eco-
house
geo-
land, earth
herba-
grass, plants
lateral-
side
nomy-
ordered knowledge, law
phag-
eat
photo-
light
zoo-
animal