chap 9- glossary Flashcards
amino acid sequence
Amino Acid Sequence- the primary structure of a protein; comprises the order of the 20 possible amino acids in the polypeptide, sometimes referred to as ‘polypeptide sequence’.
antibiotic resistance
Antibiotic resistance- the capacity for a microbe to withstand the lethal effects of an antibiotic to which it was once susceptible.
antibiotic resistance gene
Antibiotic resistance gene- a gene that codes for an antibiotic resistant phenotype.
antigenic drift
Antigenic drift- a change in the antigen of a virus that would otherwise be recognisable by the adaptive immune system, resulting from the gradual accumulation of mutations in the virus.
antigenic shift
Antigenic shift- a sudden change in the antigen of a virus resulting from the rearrangement of genetic material from two or more strains or subtypes of the virus.
artificial selection
Artificial selection- breeding of plants and animals over successive generations to produce traits hat are desirable to humans; also known as ‘selective breeding’.
beneficial mutation
Beneficial mutation- a mutation that increases the organisms chances of survival and reproduction.
block mutation
Block mutation- a mutation involving rearrangements of chromosomal segments.
bottleneck effect
Bottleneck effect- when a catastrophic event or a period of adverse conditions drastically reduces the size of a population and its genetic diversity.
broad spectrum
Broad spectrum- describes an antibiotic (or insecticide) that is effective against a variety of organisms.
conserved
Conserved- amino acids of polypeptide sequences or nucleotides of DNA sequences that remain consistent across species.
deleterious mutation
Deleterious mutation- a mutation that decreases the organisms chances of survival and reproduction.
deletion mutation
Deletion mutation- a mutation in which nucleotide pairs have been lost from a segment of DNA.
double-strand break
Double-strand break- a mutation involving breaks in the sugar-phosphate backbones at the same nucleotide pair, resulting in the complete breakage of a chromosome.
duplication
Duplication- a mutation that occurs when one or more extra copies are made of a section of chromosome.
extinct
Extinct- when al the members of a population or species have died out.
fitness
Fitness- the capacity of an individual to survive and produce viable offspring.
fixed
Fixed- describes an allele when it is the only variant available for a particular gene in the gene pool of a population.
founder effect
Founder effect- the type of gene flow that occurs when a few individuals that have become isolated from a larger population do not carry all the alleles that were present in the original population.
gene duplication
Gene duplication- generating an extra copy of a gene within a genome as a result of duplication of a chromosomal segment.
gene flow
Gene flow- the transfer of alleles that results from emigration and immigration of individuals between populations.
gene pool
Gene pool- the range of genes and all their alleles present in a population.
gene sequence
Gene sequence- the sequence of nucleotides in a gene.
genetic drift
Genetic drift- the change in the gene pool of a population as a result of chance, usually occurs in small populations.
genotype
Genotype- a specific combination of alleles for a particular gene locus belonging to an individual.
germline
Germline- a cell line in eukaryotic organisms from which the gametes are derived.
heritable
Heritable- capable of being passed on to the next generation.
horizontal gene transfer
Horizontal gene transfer- the process by which genetic material from one organism becomes incorporated into the genome of another organism.
insertion mutation
Insertion mutation- a mutation in which nucleotide pairs have been added to a segment of DNA.
inversion mutation
Inversion mutation- a mutation resulting in the normal sequence of genes being reversed in a chromosome.
missense mutation
Missense mutation- a mutation that results in one amino acid being replaced by another amino acid in the encoded protein.
monoculture
Monoculture- the practice of cultivating a single genetically uniform breed of plant or livestock.
multidrug resistance
Multidrug resistance- when a bacterium becomes resistant to two or more antibiotics.
mutagen
Mutagen- an agent capable of inducing mutations.
mutation
Mutation- when a gene or chromosome has undergone a change relative to the original gene or chromosome; it may also refer to he process of generating such changes.
natural selection
Natural selection- the process whereby individuals with certain heritable traits survive and reproduce more successfully than other individuals.
neutral mutation
Neutral mutation- a mutation that has no effect on the organisms chances of survival and reproduction.
nonsense mutation
Nonsense mutation- a mutation in which a codon for an amino acid is changed to one that codes for a stop codon, terminating translation.
phenotype
Phenotype- the actual form taken by a specific feature in a particular individual based on their genotype; can be used in reference to particular traits or characteristics or to the overall form of an individual.
point mutation
Point mutation- a mutation that affects a single base-pair position within a gene.
population
Population- a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.
population genetics
Population genetics- the study of allele frequencies in population and how they change over time.
selection pressure
Selection pressure- a factor that favours the survival of some individuals over others within a population.
silent mutation
Silent mutation- a mutation in which the DNA codon for one amino acid becomes another DNA codon for the same amino acid; also referred to as synonymous mutation.
somatic
Somatic- describes a body cell that will not pass its genes on to the next generation.
species
Species- a group of similar organisms capable of breeding and exchanging genes with one another and whose offspring are capable of doing he same; also describes the lowest formal taxonomic rank and forms the second part of an organisms scientific name.
subspecies
Subspecies- the level of classification below species, referring to races of a species that are geographically isolated from each other.
substitution mutation
Substitution mutation- a mutation in which a single nucleotide is swapped for another in the original gene sequence.
translocation
Translocation- a mutation occurring when a section of one chromosome breaks off and reattaches to another chromosome.
