Biology Final

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