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post-transcriptional : control of gene expression after the RNA molecule has been created but before it is translated into protein
https://openstax.org/books/concepts-biology/pages/9-key-terms
post-translational : control of gene expression after a protein has been created
https://openstax.org/books/concepts-biology/pages/9-key-terms
primer : a short stretch of RNA nucleotides that is required to initiate replication and allow DNA polymerase to bind and begin replication
https://openstax.org/books/concepts-biology/pages/9-key-terms
promoter : a sequence on DNA to which RNA polymerase and associated factors bind and initiate transcription
https://openstax.org/books/concepts-biology/pages/9-key-terms
replication fork : the Y-shaped structure formed during the initiation of replication
https://openstax.org/books/concepts-biology/pages/9-key-terms
RNA polymerase : an enzyme that synthesizes an RNA strand from a DNA template strand
https://openstax.org/books/concepts-biology/pages/9-key-terms
rRNA : ribosomal RNA; molecules of RNA that combine to form part of the ribosome
https://openstax.org/books/concepts-biology/pages/9-key-terms
semiconservative replication : the method used to replicate DNA in which the double-stranded molecule is separated and each strand acts as a template for a new strand to be synthesized, so the resulting DNA molecules are composed of one new strand of nucleotides and one old strand of nucleotides
https://openstax.org/books/concepts-biology/pages/9-key-terms
splicing : the process of removing introns and reconnecting exons in a pre-mRNA
https://openstax.org/books/concepts-biology/pages/9-key-terms
start codon : the AUG (or, rarely GUG) on an mRNA from which translation begins; always specifies methionine
https://openstax.org/books/concepts-biology/pages/9-key-terms
stop codon : one of the three mRNA codons that specifies termination of translation
https://openstax.org/books/concepts-biology/pages/9-key-terms
telomerase : an enzyme that contains a catalytic part and an inbuilt RNA template; it functions to maintain telomeres at chromosome ends
https://openstax.org/books/concepts-biology/pages/9-key-terms
telomere : the DNA at the end of linear chromosomes
https://openstax.org/books/concepts-biology/pages/9-key-terms
template strand : the strand of DNA that specifies the complementary mRNA molecule
https://openstax.org/books/concepts-biology/pages/9-key-terms
transcription bubble : the region of locally unwound DNA that allows for transcription of mRNA
https://openstax.org/books/concepts-biology/pages/9-key-terms
tRNA : transfer RNA; an RNA molecule that contains a specific three-nucleotide anticodon sequence to pair with the mRNA codon and also binds to a specific amino acid
https://openstax.org/books/concepts-biology/pages/9-key-terms
Nucleic acids can be isolated from cells for the purposes of further analysis by breaking open the cells and enzymatically destroying all other major macromolecules. Fragmented or whole chromosomes can be separated on the basis of size by gel electrophoresis. Short stretches of DNA can be amplified by PCR. DNA can be c...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Cloning may involve cloning small DNA fragments (molecular cloning), or cloning entire organisms (reproductive cloning). In molecular cloning with bacteria, a desired DNA fragment is inserted into a bacterial plasmid using restriction enzymes and the plasmid is taken up by a bacterium, which will then express the forei...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
In reverse genetics methods, a gene is mutated or removed in some way to identify its effect on the phenotype of the whole organism as a way to determine its function.
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Genetic testing is performed to identify disease-causing genes, and can be used to benefit affected individuals and their relatives who have not developed disease symptoms yet. Gene therapy—by which functioning genes are incorporated into the genomes of individuals with a non-functioning mutant gene—has the potenti...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Genes are inserted into plants, using plasmids in the bacteriumAgrobacterium tumefaciens, which infects plants. Transgenic plants have been created to improve the characteristics of crop plants—for example, by giving them insect resistance by inserting a gene for a bacterial toxin.
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Genome mapping is similar to solving a big, complicated puzzle with pieces of information coming from laboratories all over the world. Genetic maps provide an outline for the location of genes within a genome, and they estimate the distance between genes and genetic markers on the basis of the recombination frequency d...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Whole genome sequencing is the latest available resource to treat genetic diseases. Some doctors are using whole genome sequencing to save lives. Genomics has many industrial applications, including biofuel development, agriculture, pharmaceuticals, and pollution control.
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Imagination is the only barrier to the applicability of genomics. Genomics is being applied to most fields of biology; it can be used for personalized medicine, prediction of disease risks at an individual level, the study of drug interactions before the conduction of clinical trials, and the study of microorganisms in...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
Proteomics is the study of the entire set of proteins expressed by a given type of cell under certain environmental conditions. In a multicellular organism, different cell types will have different proteomes, and these will vary with changes in the environment. Unlike a genome, a proteome is dynamic and under constant ...
https://openstax.org/books/concepts-biology/pages/10-chapter-summary
anneal : in molecular biology, the process by which two single strands of DNA hydrogen bond at complementary nucleotides to form a double-stranded molecule
https://openstax.org/books/concepts-biology/pages/10-key-terms
biomarker : an individual protein that is uniquely produced in a diseased state
https://openstax.org/books/concepts-biology/pages/10-key-terms
biotechnology : the use of artificial methods to modify the genetic material of living organisms or cells to produce novel compounds or to perform new functions
https://openstax.org/books/concepts-biology/pages/10-key-terms
cloning : the production of an exact copy—specifically, an exact genetic copy—of a gene, cell, or organism
https://openstax.org/books/concepts-biology/pages/10-key-terms
gel electrophoresis : a technique used to separate molecules on the basis of their ability to migrate through a semisolid gel in response to an electric current
https://openstax.org/books/concepts-biology/pages/10-key-terms
gene therapy : the technique used to cure heritable diseases by replacing mutant genes with good genes
https://openstax.org/books/concepts-biology/pages/10-key-terms
genetic engineering : alteration of the genetic makeup of an organism using the molecular methods of biotechnology
https://openstax.org/books/concepts-biology/pages/10-key-terms
genetic map : an outline of genes and their location on a chromosome that is based on recombination frequencies between markers
https://openstax.org/books/concepts-biology/pages/10-key-terms
genetic testing : identifying gene variants in an individual that may lead to a genetic disease in that individual
https://openstax.org/books/concepts-biology/pages/10-key-terms
genetically modified organism (GMO) : an organism whose genome has been artificially changed
https://openstax.org/books/concepts-biology/pages/10-key-terms
genomics : the study of entire genomes, including the complete set of genes, their nucleotide sequence and organization, and their interactions within a species and with other species
https://openstax.org/books/concepts-biology/pages/10-key-terms
metagenomics : the study of the collective genomes of multiple species that grow and interact in an environmental niche
https://openstax.org/books/concepts-biology/pages/10-key-terms
model organism : a species that is studied and used as a model to understand the biological processes in other species represented by the model organism
https://openstax.org/books/concepts-biology/pages/10-key-terms
pharmacogenomics : the study of drug interactions with the genome or proteome; also called toxicogenomics
https://openstax.org/books/concepts-biology/pages/10-key-terms
physical map : a representation of the physical distance between genes or genetic markers
https://openstax.org/books/concepts-biology/pages/10-key-terms
plasmid : a small circular molecule of DNA found in bacteria that replicates independently of the main bacterial chromosome; plasmids code for some important traits for bacteria and can be used as vectors to transport DNA into bacteria in genetic engineering applications
https://openstax.org/books/concepts-biology/pages/10-key-terms
polymerase chain reaction (PCR) : a technique used to make multiple copies of DNA
https://openstax.org/books/concepts-biology/pages/10-key-terms
protein signature : a set of over- or under-expressed proteins characteristic of cells in a particular diseased tissue
https://openstax.org/books/concepts-biology/pages/10-key-terms
proteomics : study of the function of proteomes
https://openstax.org/books/concepts-biology/pages/10-key-terms
recombinant DNA : a combination of DNA fragments generated by molecular cloning that does not exist in nature
https://openstax.org/books/concepts-biology/pages/10-key-terms
recombinant protein : a protein that is expressed from recombinant DNA molecules
https://openstax.org/books/concepts-biology/pages/10-key-terms
reproductive cloning : cloning of entire organisms
https://openstax.org/books/concepts-biology/pages/10-key-terms
restriction enzyme : an enzyme that recognizes a specific nucleotide sequence in DNA and cuts the DNA double strand at that recognition site, often with a staggered cut leaving short single strands or “sticky” ends
https://openstax.org/books/concepts-biology/pages/10-key-terms
reverse genetics : a form of genetic analysis that manipulates DNA to disrupt or affect the product of a gene to analyze the gene’s function
https://openstax.org/books/concepts-biology/pages/10-key-terms
transgenic : describing an organism that receives DNA from a different species
https://openstax.org/books/concepts-biology/pages/10-key-terms
whole genome sequencing : a process that determines the nucleotide sequence of an entire genome
https://openstax.org/books/concepts-biology/pages/10-key-terms
Evolution by natural selection arises from three conditions: individuals within a species vary, some of those variations are heritable, and organisms have more offspring than resources can support. The consequence is that individuals with relatively advantageous variations will be more likely to survive and have higher...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
The modern synthesis of evolutionary theory grew out of the reconciliation of Darwin’s, Wallace’s, and Mendel’s thoughts on evolution and heredity. Population genetics is a theoretical framework for describing evolutionary change in populations through the change in allele frequencies. Population genetics defines...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
There are four factors that can change the allele frequencies of a population. Natural selection works by selecting for alleles that confer beneficial traits or behaviors, while selecting against those for deleterious qualities. Mutations introduce new alleles into a population. Genetic drift stems from the chance occu...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
The evidence for evolution is found at all levels of organization in living things and in the extinct species we know about through fossils. Fossils provide evidence for the evolutionary change through now extinct forms that led to modern species. For example, there is a rich fossil record that shows the evolutionary t...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
Speciation occurs along two main pathways: geographic separation (allopatric speciation) and through mechanisms that occur within a shared habitat (sympatric speciation). Both pathways force reproductive isolation between populations. Sympatric speciation can occur through errors in meiosis that form gametes with extra...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
The theory of evolution is a difficult concept and misconceptions abound. The factual nature of evolution is often challenged by wrongly associating the scientific meaning of a theory with the vernacular meaning. Evolution is sometimes mistakenly interpreted to mean that individuals evolve, when in fact only population...
https://openstax.org/books/concepts-biology/pages/11-chapter-summary
adaptation : a heritable trait or behavior in an organism that aids in its survival in its present environment
https://openstax.org/books/concepts-biology/pages/11-key-terms
adaptive radiation : a speciation when one species radiates out to form several other species
https://openstax.org/books/concepts-biology/pages/11-key-terms
allopatric speciation : a speciation that occurs via a geographic separation
https://openstax.org/books/concepts-biology/pages/11-key-terms
analogous structure : a structure that is similar because of evolution in response to similar selection pressures resulting in convergent evolution, not similar because of descent from a common ancestor
https://openstax.org/books/concepts-biology/pages/11-key-terms
bottleneck effect : the magnification of genetic drift as a result of natural events or catastrophes
https://openstax.org/books/concepts-biology/pages/11-key-terms
convergent evolution : an evolution that results in similar forms on different species
https://openstax.org/books/concepts-biology/pages/11-key-terms
dispersal : an allopatric speciation that occurs when a few members of a species move to a new geographical area
https://openstax.org/books/concepts-biology/pages/11-key-terms
divergent evolution : an evolution that results in different forms in two species with a common ancestor
https://openstax.org/books/concepts-biology/pages/11-key-terms
founder effect : a magnification of genetic drift in a small population that migrates away from a large parent population carrying with it an unrepresentative set of alleles
https://openstax.org/books/concepts-biology/pages/11-key-terms
gene flow : the flow of alleles in and out of a population due to the migration of individuals or gametes
https://openstax.org/books/concepts-biology/pages/11-key-terms
gene pool : all of the alleles carried by all of the individuals in the population
https://openstax.org/books/concepts-biology/pages/11-key-terms
genetic drift : the effect of chance on a population’s gene pool
https://openstax.org/books/concepts-biology/pages/11-key-terms
homologous structure : a structure that is similar because of descent from a common ancestor
https://openstax.org/books/concepts-biology/pages/11-key-terms
inheritance of acquired characteristics : a phrase that describes the mechanism of evolution proposed by Lamarck in which traits acquired by individuals through use or disuse could be passed on to their offspring thus leading to evolutionary change in the population
https://openstax.org/books/concepts-biology/pages/11-key-terms
macroevolution : a broader scale of evolutionary changes seen over paleontological time
https://openstax.org/books/concepts-biology/pages/11-key-terms
microevolution : the changes in a population’s genetic structure (i.e., allele frequency)
https://openstax.org/books/concepts-biology/pages/11-key-terms
migration : the movement of individuals of a population to a new location; in population genetics it refers to the movement of individuals and their alleles from one population to another, potentially changing allele frequencies in both the old and the new population
https://openstax.org/books/concepts-biology/pages/11-key-terms
modern synthesis : the overarching evolutionary paradigm that took shape by the 1940s and is generally accepted today
https://openstax.org/books/concepts-biology/pages/11-key-terms
natural selection : the greater relative survival and reproduction of individuals in a population that have favorable heritable traits, leading to evolutionary change
https://openstax.org/books/concepts-biology/pages/11-key-terms
population genetics : the study of how selective forces change the allele frequencies in a population over time
https://openstax.org/books/concepts-biology/pages/11-key-terms
speciation : a formation of a new species
https://openstax.org/books/concepts-biology/pages/11-key-terms
sympatric speciation : a speciation that occurs in the same geographic space
https://openstax.org/books/concepts-biology/pages/11-key-terms
variation : the variety of alleles in a population
https://openstax.org/books/concepts-biology/pages/11-key-terms
vestigial structure : a physical structure present in an organism but that has no apparent function and appears to be from a functional structure in a distant ancestor
https://openstax.org/books/concepts-biology/pages/11-key-terms
vicariance : an allopatric speciation that occurs when something in the environment separates organisms of the same species into separate groups
https://openstax.org/books/concepts-biology/pages/11-key-terms
Scientists continually obtain new information that helps to understand the evolutionary history of life on Earth. Each group of organisms went through its own evolutionary journey, called its phylogeny. Each organism shares relatedness with others, and based on morphologic and genetic evidence scientists attempt to map...
https://openstax.org/books/concepts-biology/pages/12-chapter-summary
To build phylogenetic trees, scientists must collect character information that allows them to make evolutionary connections between organisms. Using morphologic and molecular data, scientists work to identify homologous characteristics and genes. Similarities between organisms can stem either from shared evolutionary ...
https://openstax.org/books/concepts-biology/pages/12-chapter-summary
analogous structure : a character found in two taxa that looks similar because of convergent evolution, not because of descent from a common ancestor
https://openstax.org/books/concepts-biology/pages/12-key-terms
binomial nomenclature : a system of two-part scientific names for an organism, which includes genus and species names
https://openstax.org/books/concepts-biology/pages/12-key-terms
branch point : a point on a phylogenetic tree where a single lineage splits to distinct new ones
https://openstax.org/books/concepts-biology/pages/12-key-terms
clade : a group of taxa with the same set of shared derived characters, including an ancestral species and all its descendants
https://openstax.org/books/concepts-biology/pages/12-key-terms
cladistics : a method used to organize homologous traits to describe phylogenies using common descendent as the primary criterion used to classify organisms
https://openstax.org/books/concepts-biology/pages/12-key-terms
class : the category in the taxonomic classification system that falls within phylum and includes orders
https://openstax.org/books/concepts-biology/pages/12-key-terms
domain : the highest level category in the classification system and that includes all taxonomic classifications below it; it is the most inclusive taxon
https://openstax.org/books/concepts-biology/pages/12-key-terms
family : the category in the taxonomic classification system that falls within order and includes genera
https://openstax.org/books/concepts-biology/pages/12-key-terms
genus : the category in the taxonomic classification system that falls within family and includes species; the first part of the scientific name
https://openstax.org/books/concepts-biology/pages/12-key-terms
kingdom : the category in the taxonomic classification system that falls within domain and includes phyla
https://openstax.org/books/concepts-biology/pages/12-key-terms
maximum parsimony : applying the simplest, most obvious way with the least number of steps
https://openstax.org/books/concepts-biology/pages/12-key-terms
molecular systematics : the methods of using molecular evidence to identify phylogenetic relationships
https://openstax.org/books/concepts-biology/pages/12-key-terms
monophyletic group : (also, clade) organisms that share a single ancestor
https://openstax.org/books/concepts-biology/pages/12-key-terms
order : the category in the taxonomic classification system that falls within class and includes families
https://openstax.org/books/concepts-biology/pages/12-key-terms
phylogenetic tree : diagram used to reflect the evolutionary relationships between organisms or groups of organisms
https://openstax.org/books/concepts-biology/pages/12-key-terms
phylogeny : evolutionary history and relationship of an organism or group of organisms
https://openstax.org/books/concepts-biology/pages/12-key-terms