copy

Y chromosome

...ost males with Klinefelter syndrome have one extra copy of the X chromosome in each cell (47,XXY). Variant...es with variant Klinefelter syndrome have an extra copy of both the X and Y chromosomes, for a total of two X chromosomes and two Y chromosomes (48,XXYY) in...

X chromosome

...ures that females, like males, have one functional copy of the X chromosome in each body cell. Identifyin...body , and it was previously assumed that only one copy is actively used. However, recent research (Carrel & Willard 2005) suggests that the Barr body m...

Virus

...led RNA replicase . This enzyme then uses that RNA copy as a template to make hundreds of duplicates of the original RNA. A second group of RNA-containing viruses, called the retroviruses , uses the enzyme reverse transcriptase to synthesize a complementary strand of DNA so that the virus's genetic inf...

Mitosis

...res that each daughter nucleus receives a complete copy of the organism's genome. In most eukaryotes mito...s again. The goal of mitosis is to assure that one copy of each sister chromatid — and only one copy — goes to each daughter cell after cell div...

Reproduction

Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing...by which an organism creates a genetically similar copy of itself without the combination of genetic material with another individual. For example, the Hy...

RNA

... thymine . One of the main functions of RNA is to copy genetic information from DNA (via transcription ) and then translate it into proteins (by translation ). Contents showTocToggle("show","hide") 1 Chemical structure 2 Comparison to DNA 3 Synthesis 4 RNA world hypothe...

Replication

... act of a molecule (or any other pattern) making a copy of itself. DNA replication is the act of co... which usually means, that each node have separate copy (replica) of this page. In statistics replication refers to repeated measurement of a phenomenon...

Protein biosynthesis

...is opposite to the coding strand (the cell wants a copy of the coding strand, so it needs to copy that from the DNA that is the opposite of the coding strand), it matches corresponding mRNA nucleoti...

Prophase

...s again. The task of mitosis is to assure that one copy of each sister chromatid - and only one copy - goes to each daughter cell after cell division. The other important piece of hardware in mitosis ...

Plasmid

...nal groups. Plasmids that exist only as a single copy in each bacterium are, upon cell division , in da...ave systems which attempt to actively distribute a copy to both daughter cells. Some plasmids include an addiction system . They produce both a long-lived...

Polymerase chain reaction

...s opposed to living organisms, the PCR process can copy only short DNA fragments, usually up to 10 kb (kb=... acids) called base pairs . Certain methods can copy fragments up to 40 kb in size, which is still much less than the chromosomal DNA of a eukaryotic c...

Patau syndrome

...r when only some of the body's cells have an extra copy of chromosome 13, resulting in a mixed population ...or example, an egg or sperm cell may gain an extra copy of chromosome 13. If one of these atypical reproductive cells contributes to the genetic makeup of a...

Parthenogenesis

...m their father; instead the eggs contains an exact copy of the chromosomes those offspring got from their own mother. This process continues, so that each generation is half (or hemi-) clonal on the mother's side and half new genetic material from the father's side. This form of reproduction is seen in ...

Muller's ratchet

... descendants have no opportunity to receive a good copy of the gene. If the other mutation is advantageous, their survival means that the deleterious mutation persists. These deleterious mutations resemble the operation of a ratchet , in that the organism can never go back. By contrast, sexual reproduct...

Molecular biology

...unctions range from serving as a temporary working copy of DNA to actual structural and enzymatic functions as well as a functional and structural part of the translational apparatus; and proteins , the major structural and enzymatic type of molecule in cells . Expression cloning One of the most...

Mitosis

...res that each daughter nucleus receives a complete copy of the organism's genome. In most eukaryotes mito...s again. The goal of mitosis is to assure that one copy of each sister chromatid — and only one copy — goes to each daughter cell after cell div...

Heterozygote

...person at all if the other chromosome has a normal copy of the gene; this would be referred to as a recessive disease. To describe how a trait inherits ( Main article: Mendelian inheritance ), the dominant trait is indicated with a capital and the recessive with a lower case character. The colour of...

Hardy-Weinberg principle

...rogametic sex (e.g. males in humans) have only one copy of the gene and are effectively haploid for that g...d population". Science 28 : 49–50. ESP copy Pearson, K. ( 1904 ). Mathematical contributions to the theory of evolution. XI. On the influenc...

Ploidy

...id (meaning simple in Greek ) cells bear one copy of each chromosome . Most fungi , and a few algae exist as haploid organisms, male bees, wasps and ants are also haploid. For organisms that only ever have one set of chromosomes, the term monoploid can be used interchangably with haploid. ...

Gregor Mendel

... (as evidenced by his notes in the margin of the copy in his monastery), but apparently failed to realize its significance. Darwin received a copy of Mendel's paper, but he did not read it (as evidenced by the pages of the paper remaining uncut). ...

Gene therapy

...NA molecule from the retrovirus must produce a DNA copy from its RNA molecule before it can be considered ...l of the host cell. The process of producing a DNA copy from an RNA molecule is termed reverse transcription . It is carried out by one of the enzymes carr...

Gene duplication

...ne is duplicated selection may be removed from one copy and now the other gene locus is free to mutate and discover new functions. Alternatively, the gene may acquire deleterious mutations and become a pseudogene . The postulate that gene duplication has a major role in evolution was developed in the ...

Gene

... Y chromosome . Many species carry more than one copy of their genome within each of their somatic cells . These organisms are called diploid if they have two copies, or polyploid if they have more than two copies. In such organisms, the copies are practically never identical. With respect to eac...

Gamete

... somatic cells of an individual will contain one copy of the chromosome set from the sperm and one copy of the chromosome set from the egg—that is, the cells of the offspring will have genes express...

Eukaryote

... which allows each daughter nucleus to receive one copy of each chromosome. In most eukaryotes there is al...tion between haploid generations, where only one copy of each chromosome is present, and diploid generations, where two are present, occurring through n...

Edward's syndrome

...r when only some of the body's cells have an extra copy of chromosome 18, resulting in a mixed population of cells with a differing number of chromosomes. Such cases are sometimes called mosaic Edwards syndrome. Very rarely, a piece of chromosome 18 becomes attached to another chromosome ( translocated ...

Down syndrome

...f cases). Trisomy 21 is the existence of the third copy of the chromosome 21 in cells throughout the body of the affected person. Other Down syndrome disorders are based on the duplication of the same subset of genes (e.g., various translocations of chromosome 21). Depending on the actual etiology , ...

DNA

...s in replication can result in a less than perfect copy (see mutation ), and each of them consists of one original and one newly synthesized strand. This is called semiconservative replication . The process of replication consists of three steps: initiation , replication and termination . Mech...

Ploidy

...id (meaning simple in Greek ) cells bear one copy of each chromosome . Most fungi , and a few algae exist as haploid organisms, male bees, wasps and ants are also haploid. For organisms that only ever have one set of chromosomes, the term monoploid can be used interchangably with haploid. ...

Cloning

Cloning is the process of creating an identical copy of an original. A clone in the biological sens..., but in common parlance the clone is an identical copy by some conscious design. Also see clone (genetics) . The term clone is derived from κ&la...

Cell growth

...eplicate their chromosomes to an abnormally high copy number or become multinucleated. Large cells that ...sure that each of the four daughter cells gets one copy of each of the 23 types of chromosome (see meiosis for details). Why we have sex Main article...

Bacterial conjugation

...replication , called oriV . There can only be one copy of the F-plasmid in a bacterium (which is then called F-positive ), either free or integrated. Among other genetic information, the F-plasmid carries a tra and a trb locus , which together are about 33 kb long and consist of about 40 genes . ...

Autosome

...autosome and is always expressed, even if a single copy exists. The chance is 1:2 for passing this gene to offspring....

Reproduction

Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing...by which an organism creates a genetically similar copy of itself without the combination of genetic material with another individual. For example, the Hy...

Allele frequency

...l be heterozygous for the allele (i.e. carry one copy of that allele and one copy of another in each somatic cell) and 4% will be homozygous (carrying two copies of the allele). S...