...transcription of specific genes. In the case...
...transcription of specific genes) or negative transcription...
...expression of other genes normally activated by...
...by turning specific genes on and off....
...the expression of genes, affecting the activity...
...expression of other genes. Auxin stimulates a...
...expression of certain genes. ABA is the...
...expression of new genes, which produce enzymes...
...one of the genes required for ethylene...
...identify all the genes in a plant....
...can determine which genes are inactivated or...
...change. Identifying the genes and proteins in...
...will record which genes in a plant’s...
...of certain photosynthesis-related genes that show circadian...
...of the photosynthesis genes in Arabidopsis, it...
...that meristem identity genes that induce the...
...Then organ identity genes that specify the...
...activity of specific genes, some of which...
...plant activate defense genes whose expression patterns...
...disease resistance (R) genes. There are many...
...have many R genes; Arabidopsis has several...
...of some defense genes, including those that...

...develop cause different genes involved in leaf...
...of about 26,000 genes, with fewer than...
...different types of genes. Now that the...
...of the plant’s genes. To aid in...
...functions of these genes has already expanded...
...visualize which plant genes are activated in...
...and leaves. Other genes that regulate pattern...
...include master regulatory genes called homeotic genes,...
...genes called homeotic genes, which mediate many...
...selectively express certain genes at specific times...
...inactivation of specific genes involved in cellular...
...of each shoot. Genes controlling transcription play...
...floral meristem identity genes. The protein products...
...products of these genes are transcription factors...
...help activate the genes required for the...
...whorl. Organ identity genes, or plant homeotic...
...or plant homeotic genes, regulate positional information...
...Mutations in these genes may lead to...
...one. Organ identity genes code for transcription...
...which organ identity genes are expressed in...
...of organ identity genes interact to produce...
...identifies how these genes direct the formation...
...of organ identity genes is switched “on”...
...floral meristem. A genes are switched on...
...and petals), B genes are switched on...
...stamens), and C genes are switched on...
...which only A genes are active. Petals...
...A and B genes are active. Stamens...
...B and C genes are active. Carpels...
...which only C genes are active. The...

...homeobox-containing family of genes known as Hox...
...known as Hox genes. All eukaryotes have...
...All eukaryotes have genes that regulate the...
...expression of other genes. Many of these...
...of these regulatory genes contain common modules...
...animals share Hox genes, this gene family...
...to animals. Hox genes play important roles...
...hundreds of other genes that influence animal...
...animal morphology. Hox genes in sponges regulate...
...other animals, Hox genes regulate patterning of...
...based on mitochondrial genes, ribosomal genes, Hox...
...mitochondrial genes, ribosomal genes, Hox genes, and...
...ribosomal genes, Hox genes, and dozens of...
...dozens of protein-encoding genes suggest a different...
...analyses of multiple genes across a wide...

...yet have plastid genes in their nuclear...
...evidence of plastid genes. The alveolates have...
...of the parasite’s genes at specific points...
...ciliate’s genome. Macronuclear genes control the everyday...
...sexual shuffling of genes occurs during conjugation,...
...oomycete has acquired genes that make it...
...by transferring blight-resistant genes from wild potatoes....
...on hundreds of genes. Other studies based...
...based on single genes do not provide...
...based on different genes provide conflicting results....

...only a few genes. Although the general...
...4,300 E. coli genes are considered, 9...
...phage carries bacterial genes from one host...
...“mate” receives the genes. A hollow sex...
...of about 25 genes, most required for...
...bacterium that has genes derived from two...
...bacteria have resistance genes coding for enzymes...
...or ampicillin. The genes conferring resistance are...
...plasmids also have genes that encode for...
...many as ten genes for resistance to...
...sequences of prokaryotic genes in the 1970s....
...to sequence the genes of prokaryotes, they...
...to analyze the genes of prokaryotes that...
...prokaryotes have acquired genes from distantly related...
...actually mosaics of genes imported from other...
...large array of genes involved in synthesizing...
...bacterium activate human genes that build the...
...of prokaryotes enables genes conferring resistance to...
...natural selection. These genes can spread to...
...can also spread genes associated with virulence,...
...Of the 5,416 genes in O157:H7, 1,387...
...strain. These 1,387 genes must have been...
...of the imported genes are associated with...
...For example, some genes code for adhesive...

...descent. Organisms share genes, metabolic pathways, and...
...“reservoirs” of beneficial genes. These genes may...
...beneficial genes. These genes may be transferred...
...More likely, the genes involved in the...
...applies to comparing genes, which are sequences...
...species. If the genes in two organisms...
...likely that the genes are homologous. It...
...fact that different genes evolve at different...
...sequences in these genes can be compared...
...the number of genes in the genome,...
...groups of related genes within an organism’s...
...genome. Like homologous genes in different species,...
...species, these duplicated genes have a common...
...types of homologous genes: orthologous genes and...
...homologous genes: orthologous genes and paralogous genes....
...genes and paralogous genes. Orthologous genes are...
...paralogous genes. Orthologous genes are homologous genes...
...genes are homologous genes found in different...
...The ß hemoglobin genes in humans and...
...are orthologous. Paralogous genes result from gene...
...genome. Olfactory receptor genes have undergone many...
...of these paralogous genes. Most of the...
...Most of the genes that make up...
...of homology. Orthologous genes diverge after speciation...
...hemoglobin gene. Paralogous genes can diverge within...
...genome. The paralogous genes of the human...
...have emerged. Orthologous genes are widespread and...
...99% of the genes of humans and...
...50% of human genes are orthologous with...
...The number of genes seems not to...
...times as many genes as yeast, a...
...tissues. Many human genes are more versatile...
...substitutions in orthologous genes is proportional to...
...case of paralogous genes, the number of...
...time since the genes became duplicated. Scientists...
...is completely accurate. Genes that make good...
...change of various genes vary greatly. Some...
...vary greatly. Some genes evolve a million...
...evolutionary change in genes and proteins has...
...change of specific genes are a function...
...the sequence of genes is less critical,...
...even out. Even genes with irregular clocks...
...calibrated with many genes, rather than one...
...few. When many genes are used, fluctuations...
...for 658 nuclear genes. The molecular and...
...largely on rRNA genes. These genes have...
...rRNA genes. These genes have evolved so...
...be detected. Other genes reveal a different...
...of the metabolic genes in yeast are...
...similar to bacterial genes than to archaea...
...than to archaea genes. This finding suggests...
...many interchanges of genes between organisms in...
...transfer, in which genes are transferred from...
...explain why universal genes built from different...
...built from different genes give inconsistent results....

...regulation of developmental genes. The fossil record...
...mechanisms—especially changes in genes that influence development—underlie...
...differences between species. Genes that program development...
...from changes in genes that control the...
...example, master regulatory genes called homeotic genes...
...genes called homeotic genes determine such basic...
...class of homeotic genes, the Hox genes,...
...genes, the Hox genes, provide positional information...
...and Ubx Hox genes in crustaceans are...
...duplications of Hox genes found in all...
...a set of genes sufficient to produce...
...part to new genes (created by gene...
...of “hybrid” Ubx genes, each of which...
...of existing developmental genes. According to Charles...
...every stage. The genes that act as...

...discrete heritable units (genes) that retain their...
...two or more genes influence a single...
...About 14% (1,920 genes) are heterozygous, for...
...protein products of genes. This approach does...
...environmental variable. New genes and new alleles...
...point mutations in genes that code for...
...chromosome could link genes that act together...
...1,000 olfactory receptor genes and mice have...
...number of olfactory genes benefited early mammals,...
...60% of these genes have been inactivated...
...their olfactory receptor genes. Mutation rates vary...
...for every 100,000 genes) in plants and...
...or duplication of genes will modify the...
...equilibrium for specific genes. A population can...

...the sets of genes that control group-defining...
...of shared ancient genes and their products....
...whole sets of genes and their interactions,...
...locations of some genes had been identified...
...markers can be genes or any other...
...them to locate genes by testing for...
...and missing some genes in those regions....
...been determined. Protein-coding genes can be identified...
...geneticists recognize protein-coding genes from DNA sequences...
...signs of protein-coding genes. Software also looks...
...of the human genes were known before...
...of previously unknown genes come from comparing...
...those of known genes from other organisms....
...third of the genes of E. coli...
...sequenced. In these genes, function was deduced...
...on the phenotype. Genes and their products...
...entire sets of genes has encouraged scientists...
...compile catalogs of genes and proteins—listings of...
...group of interacting genes and gene products...
...of approximately 2,000 genes from the cancer...
...the known human genes. The GeneChip is...
...size, number of genes, and gene density....
...archaea have fewer genes than eukaryotes. Free-living...
...archaea have 1,500–7,500 genes, whereas the number...
...the number of genes in eukaryotes ranges...
...the number of genes in a species...
...contains roughly 20,000 genes. The D. melanogaster...
...the number of genes—only 13,700 genes. At...
...of genes—only 13,700 genes. At the outset...
...50,000 and 100,000 genes based on the...
...the number of genes in the nematode...
...with no more genes than a nematode?...
...Nearly all human genes contain multiple exons,...
...of these multi-exon genes are spliced in...
...the number of genes present in a...
...times as many genes—thus, the gene density...
...yeasts, have fewer genes per million base...
...DNA consists of genes for protein, tRNA,...
...the DNA. Bacterial genes lack introns. Most...
...as introns within genes. Introns account for...
...length between human genes (27,000 base pairs)...
...pairs) and bacterial genes (1,000 base pairs)....
...regions of protein-coding genes and the genes...
...genes and the genes for RNA products...
...conserved than protein-coding genes in these species,...
...located between functional genes, includes unique noncoding...
...pseudogenes, nonfunctional former genes that have accumulated...
...were called “jumping genes,” but in fact,...
...elements moved into genes for kernel color,...
...color, disrupting the genes so that they...
...of the human genes analyzed, suggesting that...
...of chromosomes, prevents genes from being lost...
...sequences associated with genes are included, the...
...genome. Many eukaryotic genes are present as...
...genomes, such solitary genes make up less...
...or very similar genes. In multigene families...
...tandemly. Except for genes that code for...
...final products. The genes for the three...
...families of nonidentical genes are two related...
...related families of genes that encode globins,...
...minimal number of genes, including only those...
...the evolution of genes. In a polyploid...
...one set of genes can provide essential...
...the organism. The genes in the extra...
...In this way, genes with novel functions...
...length of individual genes. Unequal crossing over...
...to duplication of genes is found in...
...the evolution of genes with related functions,...
...Each of these genes was later duplicated...
...monomers, and their genes are included in...
...differences between the genes in the globin...
...the functional globin genes provides additional evidence...
...protein product. The genes for lysozyme and...
...milk production. Both genes are found in...
...DNA sequences within genes has also contributed...
...introns in eukaryotic genes may have promoted...
...number of protein-coding genes have multiple copies...
...within or between genes owing to errors...
...recombination, disrupting cellular genes or control elements,...
...and carrying entire genes or individual exons...
...element may transfer genes to a new...
...in sequence the genes and genomes of...
...Analyzing highly conserved genes in distantly related...
...domains of life. Genes that evolved a...
...species. Several protein-coding genes in yeast are...
...some human disease genes that researchers deduced...
...of the disease genes by studying their...
...mammals. Identifying the genes shared by these...
...mammal. Identifying the genes shared by chimpanzees...
...a number of genes that are apparently...
...mouse. These include genes involved in defense...
...brain size. The genes evolving the fastest...
...markers for identifying genes that cause diseases...
...For example, homeotic genes in Drosophila specify...
...of the homeotic genes in Drosophila has...
...in the homeotic genes of many invertebrates...
...organization of these genes: The vertebrate genes...
...genes: The vertebrate genes homologous to the...
...to the homeotic genes of fruit flies...
...found in regulatory genes of much more...
...of years. Homeotic genes in animals were...
...were named Hox genes, short for homeobox-containing...
...short for homeobox-containing genes, because homeotic genes...
...genes, because homeotic genes were the first...
...were the first genes found to have...
...sequence. Other homeobox-containing genes were later found...
...act as homeotic genes and do not...
...Most of these genes are associated with...
...in the homeotic genes but also in...
...in several segmentation genes, and in a...
...protein determine which genes the protein regulates....
...batteries of developmental genes, switching them on...
...combinations of homeobox genes are active in...
...expression of regulatory genes, varying over time...
...formation. Many other genes involved in development...
...These include numerous genes that encode components...
...can the same genes be involved in...
...sequences of particular genes cause changes in...
...of the Hox genes along the body...
...turning on new genes or turning on...
...on the same genes at higher or...
...lower concentrations. Similar genes direct distinct developmental...
...shapes. Several Hox genes are expressed in...
...or turning off genes in a finely...
...transcription factors. The genes that direct these...
...are homeobox-containing Hox genes, whereas the switches...
...different family of genes, called the Mads-box...
...called the Mads-box genes. Although homeobox-containing genes...
...genes. Although homeobox-containing genes can be found...
...plants and Mads-box genes in animals, the...
...in animals, the genes do not perform...

...techniques for analyzing genes and gene expression....
...direct manipulation of genes for practical purposes....
...small number of genes that replicate independently...
...protein. Most protein-coding genes exist in only...
...different organisms. Eukaryotic genes can be cloned...
...carries two useful genes, ampR, which confers...
...of interest. Cloned genes are stored in...
...gene boundaries, some genes in either of...
...containing only the genes necessary to ensure...
...to study the genes responsible for the...
...similar or identical genes in DNA from...
...of birds. Eukaryote genes can be expressed...
...introns in eukaryotic genes may prevent the...
...expression of these genes in bacteria, which...
...and expressing eukaryotic genes. Yeast cells, single-celled...
...DNA of viral genes from cells infected...
...questions about specific genes and their functions....
...compare it to genes in other species,...
...known. If two genes from different species...
...large groups of genes, to study how...
...to study how genes act together to...
...to investigate which genes are transcribed in...
...for groups of genes that are expressed...
...the subset of genes in the genome...
...fragments representing different genes fixed to a...
...represent all the genes of an organism....
...90% of the genes of the nematode...
...60% of the genes changed dramatically during...
...during development. Many genes were expressed in...
...protocols. Scientists disable genes and observe the...
...function of the genes. In an application...
...of the 25,000 genes in the mouse...
...expression of selected genes exploits the phenomenon...
...expression of specific genes in mammalian cells,...
...86% of the genes in early nematode...
...most of the genes into a small...
...have the same genes (a concept called...
...whether cells lose genes during the process...
...expression of many genes is repressed as...
...in order for genes to be expressed...
...The identification of genes whose mutations are...
...by a person’s genes. Diseases of all...
...within the affected genes and within the...
...to cloned disease genes, and then sequencing...
...mutation. Cloned disease genes include those for...
...allelic forms of genes even in cases...
...potential. Gene therapy—introducing genes into an afflicted...
...tampering with human genes in any way...
...the transplantation of genes into somatic cells...
...change with time. Genes that are damaging...
...with rice containing genes for milk proteins,...
...for introducing new genes into plant cells...
...if cancer cell genes were transferred into...
...one or more genes from another species...
...pass their new genes on to close...
...crop plants carrying genes for resistance to...
...of information about genes. The increasing speed...