genesnumber of genesgene sequence
Recently developed genome engineering techniques use engineered nuclease enzymes to create targeted DNA repair in a chromosome to either disrupt or edit a gene when the break is repaired. The related term synthetic biology is sometimes used to refer to extensive genetic engineering of an organism. Genetic engineering is now a routine research tool with model organisms. For example, genes are easily added to bacteria and lineages of knockout mice with a specific gene's function disrupted are used to investigate that gene's function. Many organisms have been genetically modified for applications in agriculture, industrial biotechnology, and medicine.


mutationsgenetic mutationmutated
In evolution, the most important role of such chromosomal rearrangements may be to accelerate the divergence of a population into new species by making populations less likely to interbreed, thereby preserving genetic differences between these populations. Sequences of DNA that can move about the genome, such as transposons, make up a major fraction of the genetic material of plants and animals, and may have been important in the evolution of genomes. For example, more than a million copies of the Alu sequence are present in the human genome, and these sequences have now been recruited to perform functions such as regulating gene expression.

Index of genetics articles

List of genetics-related topicsIndex of genetic engineering articlesGenetic engineering topics
Genetic deletion. Genetic determinism. Genetic disorder. Genetic dissection. Genetic drift. Genetic engineering. Genetic genealogy. Genetic history of Europe. Genetic illness. Genetic informatics. Genetic linkage map. Genetic load. Genetic map. Genetic marker. Genetic material. Genetic mosaic. Genetic polymorphism. Genetic screen. Genetic screening. Genetic testing. Genetic variance. Genetic variation. Geneticist. Genetics. Genetics and Archaeogenetics of South Asia. Genetics experiments. Genic balance theory. Genome. Genome map. Genome project. Genome screen. Genomic library. Genomic sequence. Genomics. Genophore. Genotype. Germ cell. Germ line. Germ-line theory. Germinal mutation.


In addition to studying chromosomes to the level of individual genes, genetic testing in a broader sense includes biochemical tests for the possible presence of genetic diseases, or mutant forms of genes associated with increased risk of developing genetic disorders. Genetic testing identifies changes in chromosomes, genes, or proteins. Most of the time, testing is used to find changes that are associated with inherited disorders. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person's chance of developing or passing on a genetic disorder. As of 2011 several hundred genetic tests were in use.


An example of random variation in Drosophila flies is the number of ommatidia, which may vary (randomly) between left and right eyes in a single individual as much as they do between different genotypes overall, or between clones raised in different environments. The concept of phenotype can be extended to variations below the level of the gene that affect an organism's fitness. For example, silent mutations that do not change the corresponding amino acid sequence of a gene may change the frequency of guanine-cytosine base pairs (GC content).


Genetic changes can occur at different levels and by different mechanisms. The gain or loss of an entire chromosome can occur through errors in mitosis. More common are mutations, which are changes in the nucleotide sequence of genomic DNA. Large-scale mutations involve the deletion or gain of a portion of a chromosome. Genomic amplification occurs when a cell gains copies (often 20 or more) of a small chromosomal locus, usually containing one or more oncogenes and adjacent genetic material. Translocation occurs when two separate chromosomal regions become abnormally fused, often at a characteristic location.

James Watson

James D. WatsonWatsonJames Dewey Watson
Watson has repeatedly supported genetic screening and genetic engineering in public lectures and interviews, arguing that stupidity is a disease and the "really stupid" bottom 10% of people should be cured. He has also suggested that beauty could be genetically engineered, saying in 2003, "People say it would be terrible if we made all girls pretty. I think it would be great." In 2007, James Watson became the second person to publish his fully sequenced genome online, after it was presented to him on May 31, 2007, by 454 Life Sciences Corporation in collaboration with scientists at the Human Genome Sequencing Center, Baylor College of Medicine.

Outline of genetics

History of genetic engineering. History of genomics. History of paleontology. History of plant systematics. Neanderthal genome project. Timeline of paleontology. Molecules. amino acids. Nucleobase. Adenine. Cytosine. Guanine. Thymine. Uracil. Adenovirus. Antibody. Bacteria. Codon. Deoxyribonucleic acid (DNA). Messenger RNA. mRNA. Enzyme. Exon.

Gene expression

They are divided into two groups based on their degree of multiplexity. • AlloMap molecular expression testing • Bookmarking • Expressed sequence tag • Expression Atlas • Expression profiling • Gene structure • Genetic engineeringGenetically modified organism • List of biological databases • List of human genes • Oscillating gene • Paramutation • Protein production • Protein purification • Ribonomics • Ridge • Sequence profiling tool • Transcriptional bursting • Transcriptional noise • Transcript of unknown function * Plant Transcription Factor Database and Plant Transcriptional Regulation Data and Analysis Platform A constitutive gene is a gene that is transcribed continually as opposed to

Natural selection

The concept of natural selection originally developed in the absence of a valid theory of heredity; at the time of Darwin's writing, science had yet to develop modern theories of genetics. The union of traditional Darwinian evolution with subsequent discoveries in classical genetics formed the modern synthesis of the mid-20th century. The addition of molecular genetics has led to evolutionary developmental biology, which explains evolution at the molecular level. While genotypes can slowly change by random genetic drift, natural selection remains the primary explanation for adaptive evolution.


genomesgenetic materialgenomic
The film warns against a future where genomic information fuels prejudice and extreme class differences between those who can and can't afford genetically engineered children. * Bacterial genome size. Cryoconservation of animal genetic resources. Genome Browser. Genome Compiler. Genome topology. Genome-wide association study. List of sequenced animal genomes. List of sequenced archaeal genomes. List of sequenced bacterial genomes. List of sequenced eukaryotic genomes. List of sequenced fungi genomes. List of sequenced plant genomes. List of sequenced plastomes. List of sequenced protist genomes. Metagenomics. Microbiome. Molecular epidemiology. Molecular pathological epidemiology.

Polymerase chain reaction

PCRPCR amplificationpolymerase chain reaction (PCR)
Single Specific Primer-PCR (SSP-PCR): allows the amplification of double-stranded DNA even when the sequence information is available at one end only. This method permits amplification of genes for which only a partial sequence information is available, and allows unidirectional genome walking from known into unknown regions of the chromosome.

Cell (biology)

Eukaryotic genetic material is divided into different, linear molecules called chromosomes inside a discrete nucleus, usually with additional genetic material in some organelles like mitochondria and chloroplasts (see endosymbiotic theory). A human cell has genetic material contained in the cell nucleus (the nuclear genome) and in the mitochondria (the mitochondrial genome). In humans the nuclear genome is divided into 46 linear DNA molecules called chromosomes, including 22 homologous chromosome pairs and a pair of sex chromosomes. The mitochondrial genome is a circular DNA molecule distinct from the nuclear DNA.


proteinsproteinaceousstructural proteins
The development of such tools has been driven by the large amount of genomic and proteomic data available for a variety of organisms, including the human genome. It is simply impossible to study all proteins experimentally, hence only a few are subjected to laboratory experiments while computational tools are used to extrapolate to similar proteins. Such homologous proteins can be efficiently identified in distantly related organisms by sequence alignment. Genome and gene sequences can be searched by a variety of tools for certain properties. Sequence profiling tools can find restriction enzyme sites, open reading frames in nucleotide sequences, and predict secondary structures.


Bacteria can also contain plasmids, small extra-chromosomal DNAs that may contain genes for various useful functions such as antibiotic resistance, metabolic capabilities, or various virulence factors. Bacteria genomes usually encode a few hundred to a few thousand genes. The genes in bacterial genomes are usually a single continuous stretch of DNA and although several different types of introns do exist in bacteria, these are much rarer than in eukaryotes. Bacteria, as asexual organisms, inherit an identical copy of the parent's genomes and are clonal. However, all bacteria can evolve by selection on changes to their genetic material DNA caused by genetic recombination or mutations.


genomicgenome biologygenomic analysis
From the Greek ΓΕΝ gen, "gene" (gamma, epsilon, nu, epsilon) meaning "become, create, creation, birth", and subsequent variants: genealogy, genesis, genetics, genic, genomere, genotype, genus etc.While the word genome (from the German Genom, attributed to Hans Winkler) was in use in English as early as 1926, the term genomics was coined by Tom Roderick, a geneticist at the Jackson Laboratory (Bar Harbor, Maine), over beer at a meeting held in Maryland on the mapping of the human genome in 1986. Following Rosalind Franklin's confirmation of the helical structure of DNA, James D.

Restriction enzyme

restriction enzymesrestriction endonucleaserestriction endonucleases
Such artificial restriction enzymes can target large DNA sites (up to 36 bp) and can be engineered to bind to desired DNA sequences. Zinc finger nucleases are the most commonly used artificial restriction enzymes and are generally used in genetic engineering applications, but can also be used for more standard gene cloning applications. Other artificial restriction enzymes are based on the DNA binding domain of TAL effectors. In 2013, a new technology CRISPR-Cas9, based on a prokaryotic viral defense system, was engineered for editing the genome, and it was quickly adopted in laboratories. For more detail, read CRISPR (Clustered regularly interspaced short palindromic repeats).


ribonucleic aciddsRNAdouble-stranded RNA
Like DNA, RNA can carry genetic information. RNA viruses have genomes composed of RNA that encodes a number of proteins. The viral genome is replicated by some of those proteins, while other proteins protect the genome as the virus particle moves to a new host cell. Viroids are another group of pathogens, but they consist only of RNA, do not encode any protein and are replicated by a host plant cell's polymerase. Reverse transcribing viruses replicate their genomes by reverse transcribing DNA copies from their RNA; these DNA copies are then transcribed to new RNA.

Whole genome sequencing

genome sequencingfull genome sequencingsequenced
S. cerevisiae, a model organism in biology has a genome of only around 12 million nucleotide pairs, and was the first unicellular eukaryote to have its whole genome sequenced. The first multicellular eukaryote, and animal, to have its whole genome sequenced was the nematode worm: Caenorhabditis elegans in 1998. Eukaryotic genomes are sequenced by several methods including Shotgun sequencing of short DNA fragments and sequencing of larger DNA clones from DNA libraries such as bacterial artificial chromosomes (BACs) and yeast artificial chromosomes (YACs). In 1999, the entire DNA sequence of human chromosome 22, the shortest human autosome, was published.

2012 in science

It is the most potent genetic risk factor for Alzheimer's identified in the past 20 years. (Science Daily). Scientists sequence the genome of the domestic pig. The similarities between the pig and human genomes mean that the new data may have wide applications in the study and treatment of human genetic diseases. (Medical Daily) (Business Standard). Astronomers discover a wandering, starless rogue planet drifting through space around 100 light-years from Earth. (BBC). Researchers at the American National Institute of Standards and Technology (NIST) prove that single-wall carbon nanotubes may help protect DNA molecules from damage by oxidation. (PhysOrg). 15 November.

Index of biochemistry articles

carrier - genetic code - genetic drift - Genetic engineering - genetic fingerprint - genetic recombination - Genetics - Genome - genomics - genotype - glial fibrillary acidic protein - globin - glucagon - glucagon receptor - glucocorticoid receptor - glucose - glutamate - glutamate receptor - Glutamic acid - Glutamine - Glycerine - Glycine - glycine receptor - glycolipid - Glycolysis - glycoprotein - gonadorelin - gradient - granulocyte colony-stimulating factor - granulocyte colony-stimulating factor receptor - granulocyte-macrophage colony-stimulating factor - granulocyte-macrophage colony-stimulating factor receptor - granzyme - growth factor receptor - GTP-binding protein - GTPase - hair

Index of molecular biology articles

List of molecular biology topicsMolecular biology topics
- genomic clone - genomic library - genotype - germ line - glycoprotein - glycosylation - Golgi apparatus - GRE - guanine - hairpin - haploid - haploinsufficiency - helix-loop-helix - hematopoietic stem cell - hemophilia - heteroduplex DNA - heterozygous - highly conserved sequence - Hirschsprung's disease - histone - hnRNA - holoprosencephaly - homologous recombination - homology - homozygous - host strain (bacterial) - human artificial chromosome - Human Genome Project - human immunodeficiency virus - Huntington's disease - hybridization - hybridoma - hydrophilicity plot - immunoblot - immunoprecipitation - immunotherapy - in situ hybridization - in vitro translation - inducer - inherited


biologicalBiological Sciencesbiologist
DNA is found as linear chromosomes in eukaryotes, and circular chromosomes in prokaryotes. A chromosome is an organized structure consisting of DNA and histones. The set of chromosomes in a cell and any other hereditary information found in the mitochondria, chloroplasts, or other locations is collectively known as a cell's genome. In eukaryotes, genomic DNA is localized in the cell nucleus, or with small amounts in mitochondria and chloroplasts. In prokaryotes, the DNA is held within an irregularly shaped body in the cytoplasm called the nucleoid. The genetic information in a genome is held within genes, and the complete assemblage of this information in an organism is called its genotype.

DNA profiling

DNA evidenceDNA fingerprintinggenetic fingerprinting
The DNA fragments within the blot are permanently fixed to the filter, and the DNA strands are denatured. Radiolabeled probe molecules are then added that are complementary to sequences in the genome that contain repeat sequences. These repeat sequences tend to vary in length among different individuals and are called variable number tandem repeat sequences or VNTRs. The probe molecules hybridize to DNA fragments containing the repeat sequences and excess probe molecules are washed away. The blot is then exposed to an X-ray film. Fragments of DNA that have bound to the probe molecules appear as fluoresent bands on the film.


evolvedtheory of evolutionevolutionary
Portions of a DNA molecule that specify a single functional unit are called genes; different genes have different sequences of bases. Within cells, the long strands of DNA form condensed structures called chromosomes. The specific location of a DNA sequence within a chromosome is known as a locus. If the DNA sequence at a locus varies between individuals, the different forms of this sequence are called alleles. DNA sequences can change through mutations, producing new alleles. If a mutation occurs within a gene, the new allele may affect the trait that the gene controls, altering the phenotype of the organism.