It was commonly thought that most individuals were homozygous for the " wild type " allele at most gene loci, and that any alternative ' mutant ' allele was found in homozygous form in a small minority of " affected " individuals, often as genetic diseases, and more frequently in heterozygous form in " carriers " for the mutant allele.

It is now appreciated that most or all gene loci are highly polymorphic, with multiple alleles, whose frequencies vary from population to population, and that a great deal of genetic variation is hidden in the form of alleles that do not produce obvious phenotypic differences.

This is the only form of sexual reproduction that occurs within the group, though it is really more genetic reorganization than reproduction.

It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes.

The form of the flagella, the tubular cristae within the mitochondria, and other characters led to the suggestion that the desmothoracids belong among what is now the Cercozoa, which has now been confirmed by genetic studies.

* Tuberous Sclerosis ( TSC ) is a genetic disorder that causes tumors to form in many different organs, primarily in the brain, eyes, heart, kidney, skin and lungs.

They shared an interest in the fundamental problem of learning how genetic information might be stored in molecular form.

They can be hybrids produced through crossover ( a form of genetic recombination ) of chromosomes, which takes place in meiosis.

The most common form of genetic engineering involves the insertion of new genetic material at an unspecified location in the host genome.

A 2009 genetic study on this subspecies suggests that the northern Namib Desert and Etosha National Park populations form a separate subspecies.

The most common form of genetic engineering involves the insertion of a functional gene at an unspecified location in the host genome. This is accomplished by isolating and copying the gene of interest, generating a construct containing all the genetic elements for correct expression, and then inserting this construct into a random location in the host organism.

But, the work of Stephen Wurm ( 1982 ) and Malcolm Ross ( 2005 ) has provided considerable support for his once-radical idea that these languages form a single genetic unit.

According to Greenberg, Eurasiatic and Amerind form a genetic node, being more closely related to each other than either is to " the other families of the Old World ".

Gametes can be identical in form and function ( known as isogametes ), but in many cases an asymmetry has evolved such that two sex-specific types of gametes ( heterogametes ) exist: male gametes are small, motile, and optimized to transport their genetic information over a distance, while female gametes are large, non-motile and contain the nutrients necessary for the early development of the young organism.

Some are shaped like golf balls, some are shaped like pencils .… Now my main subject is the evolution of form, and the problem of how it is that you can get this diversity amid so little genetic difference, so far as we can tell, is a very interesting one.

Until recently, there has a been a dearth of strong evidence that supports this form of speciation, with a general feeling that interbreeding would soon eliminate any genetic differences that might appear.

# If they do have a demonstrable genetic relationship, do they form a valid linguistic taxon?

For example, Germanic and Iranian have a genetic relationship via Proto-Indo-European, but they do not form a valid taxon within the Indo-European language family, whereas in contrast Iranian and Indic do via Indo-Iranian, a daughter language of Proto-Indo-European that subsequently calved into Indic and Iranian.

Such zygotes contain DNA derived from both the parents, and this provides all the genetic information necessary to form a new individual.

The dengue virus genome ( genetic material ) contains about 11, 000 nucleotide bases, which code for the three different types of protein molecules ( C, prM and E ) that form the virus particle and seven other types of protein molecules ( NS1, NS2a, NS2b, NS3, NS4a, NS4b, NS5 ) that are only found in infected host cells and are required for replication of the virus.

After the discovery of the testis-determining gene SRY, many scientists shifted to the theory that the genetic mechanism that determines a fetus to develop into a male form was initiated by the SRY gene, which was thought to be responsible for the production of testosterone and its overall effects on body and brain development.

* A rare genetic condition can cause a prion-based, permanent and eventually fatal form of insomnia called fatal familial insomnia.

But there is also a firm aspect to lexicostatistics: the aspect of learning the internal organization of obvious natural genetic groups of languages as well as their more remote and elusive external links ; ;

The study of altruism was the initial impetus behind George R. Price's development of the Price equation, which is a mathematical equation used to study genetic evolution.

Ramsey ( 2004: 340 ) stated that " the genetic relationship between Korean and Japanese, if it in fact exists, is probably more complex and distant than we can imagine on the basis of our present state of knowledge ", a concept later restated by Lee ( 2011 ).

The order in which the amino acids are added is read through the genetic code from an mRNA template, which is a RNA copy of one of the organism's genes.

An allele ( or ) is one of two or more forms of a gene or a genetic locus ( generally a group of genes ).

It is also possible to see in animals that a high genetic diversity is beneficial in providing resiliency against harsh abiotic stressors.

Current hypotheses suggest that asexual reproduction may have short term benefits when rapid population growth is important or in stable environments, while sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments.

Jensen claimed, on the basis of his research, that general cognitive ability is essentially an inherited trait, determined predominantly by genetic factors rather than by environmental conditions.

The group's research is focused on autoimmune and genetic disorders of the neuromuscular junction and peripheral motor nerves.

This is called the neutral hypothesis, or genetic drift.

Another likely explanation for the loss of its eyes is that of selective neutrality and genetic drift: in the dark environment of the cave, the eyes are neither advantageous nor disadvantageous and thus any genetic factors that might impair the eyes ( or their development ) can take hold with no consequence on the individual or species.

Because there is no selection pressure for sight in this environment, any number of genetic abnormalities that give rise to the damage or loss of eyes could proliferate among the population with no effect on the fitness of the population.

However, there is not enough evidence to distinguish areal contacts from genetic relationship.

A nucleic acid is a complex, high-molecular-weight biochemical macromolecule composed of nucleotide chains that convey genetic information.

* Genetics is the study of the effect of genetic differences on organisms.

* Molecular biology is the study of molecular underpinnings of the process of replication, transcription and translation of the genetic material.

The central dogma of molecular biology where genetic material is transcribed into RNA and then translated into protein, despite being an oversimplified picture of molecular biology, still provides a good starting point for understanding the field.

Another grass species, Brachypodium distachyon is also an experimental model for understanding genetic, cellular and molecular biology.

A number of genetic disorders are caused when an individual inherits two recessive alleles for a single-gene trait.

::; Arrhythmogenic right ventricular dysplasia ( Arrhythmogenic right ventricular cardiomyopathy ): Cardiomyopathy caused by a genetic mutation of the desmosomes that connect myocytes.

Cancer is thought to be caused by the interaction between genetic susceptibility and environmental toxins.

Reasoning that eminence is caused by genetic traits, he did a study of their heritability, publishing it in 1869 as Hereditary Genius.

A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth.

Some genetic disorders are passed down from the parents ' genes, but others are always or almost always caused by new mutations or changes to the DNA.

In other cases, the same disease, such as some forms of cancer, may be caused by an inherited genetic condition in some people, by new mutations in other people, and by nongenetic causes in still other people.

Children born of close incestous unions have greatly increased risk of congenital disorders, death and disability at least in part due to genetic diseases caused by the inbreeding.

Other than myasthenia gravis, CMS is not caused by an autoimmune process, but due to synaptic malformation, which in turn is caused by genetic mutations.

In 1968 Motoo Kimura rekindled the debate with his neutral theory of molecular evolution which claims that most of the changes in the genetic material are caused by genetic drift.

Another example of an oncogene is the Bcr-Abl gene found on the Philadelphia Chromosome, a piece of genetic material seen in Chronic Myelogenous Leukemia caused by the translocation of pieces from chromosomes 9 and 22.

It has been speculated that the RNA to DNA transcription processes used by retroviruses may have first caused DNA to be used as genetic material.

This retcon itself was later retconned, in Star Trek: Enterprise, via a storyline in which it is revealed that the original, quasi-human appearance of the Klingons is due to a genetic mutation caused by an engineered virus – as it happened, " genetic engineering " ( Chief O ' Brien ) and " viral mutation " ( Dr. Bashir ) had been the guesses Worf refused to confirm or deny.

A neoplasm can be caused by an abnormal proliferation of tissues, which can be caused by genetic mutations.

Frequent hybridization and high levels of introgression have caused different species in the same populations to share up to 50 % of their genetic information.

Recent genetic investigations have caused an ongoing realignment of species and groups within the genus, and also have caused the old genus Ledum to be reclassified within subgenus Rhododendron.

This is a fertile breed ; this along with genetic evidence has caused them to be recently reclassified into the same genus, Bos.

It is thought to be caused by a combination of genetic and environmental factors.

It seeks to prevent ecological disasters caused by imported organisms or untested genetic technologies, and to augment and increase local natural capital by encouraging soil remediation, precision agriculture, and local consumption of the native species, rather than imported organisms and heavy use of pesticides.

These are normal genetic diseases caused by gene deletions or inactivation of the genes, but are unusually common because individuals are essentially hemizygous because of genomic imprinting, and therefore a single gene knock out is sufficient to cause the disease, where most cases would require both copies to be knocked out.