English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

2006-09-15 23:57:20 · 11 answers · asked by madhu p 1 in Science & Mathematics Medicine

11 answers

Life is specified by genomes. Every organism, including humans, has a genome that contains all of the biological information needed to build and maintain a living example of that organism. The biological information contained in a genome is encoded in its deoxyribonucleic acid (DNA) and is divided into discrete units called genes. Genes code for proteins that attach to the genome at the appropriate positions and switch on a series of reactions called gene expression.

good question!!!!!!!!!!!!!!!!!!!
thanks

2006-09-16 00:02:38 · answer #1 · answered by Anonymous · 2 0

In biology the genome of an organism is its whole hereditary information and is encoded in the DNA (or, for some viruses, RNA). This includes both the genes and the non-coding sequences of the DNA. The term was coined in 1920 by Hans Winkler, Professor of Botany at the University of Hamburg, Germany, as a portmanteau of the words gene and chromosome.

More precisely, the genome of an organism is a complete DNA sequence of one set of chromosomes; for example, one of the two sets that a diploid individual carries in every somatic cell. The term genome can be applied specifically to mean the complete set of nuclear DNA (i.e., the "nuclear genome") but can also be applied to organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome. When people say that the genome of a sexually reproducing species has been "sequenced," typically they are referring to a determination of the sequences of one set of autosomes and one of each type of sex chromosome, which together represent both of the possible sexes. Even in species that exist in only one sex, what is described as "a genome sequence" may be a composite from the chromosomes of various individuals. In general use, the phrase "genetic makeup" is sometimes used conversationally to mean the genome of a particular individual or organism. The study of the global properties of genomes of related organisms is usually referred to as genomics, which distinguishes it from genetics which generally studies the properties of single genes or groups of genes.
In some contexts, such as sequencing the genome of a pathogenic microbe, "genome" is meant to include this auxiliary material, which is carried in plasmids. In such circumstances then, "genome" describes all of the genes and non-coding DNA that have the potential to be present.

In vertebrates such as humans, however, "genome" carries the typical connotation of only chromosomal DNA
I answered what all i know.. If there is any mistake please rectify and forgive me. SRUJAN

2006-09-20 02:49:05 · answer #2 · answered by srujan 2 · 0 0

genome (jee-nohm)

The sum of all information contained in the DNA for any living thing. The sequence of all the nucleotides in all the chromosomes of an organism.

2006-09-16 09:06:53 · answer #3 · answered by Anonymous · 0 0

the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA

2006-09-19 10:55:27 · answer #4 · answered by doctor asho 5 · 0 0

genome is a kind of reaseach about human such as genetic sick, the type of blood, finger prints and other

2006-09-17 01:37:50 · answer #5 · answered by aishah b 1 · 0 0

In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). This includes both the genes and the non-coding sequences. The term was coined in 1920 by Hans Winkler, Professor of Botany at the University of Hamburg, Germany, as a portmanteau of the words gene and chromosome.

More precisely, the genome of an organism is a complete DNA sequence of one set of chromosomes; for example, one of the two sets that a diploid individual carries in every somatic cell. The term genome can be applied specifically to mean the complete set of nuclear DNA (i.e., the "nuclear genome") but can also be applied to organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome. When people say that the genome of a sexually reproducing species has been "sequenced," typically they are referring to a determination of the sequences of one set of autosomes and one of each type of sex chromosome, which together represent both of the possible sexes. Even in species that exist in only one sex, what is described as "a genome sequence" may be a composite from the chromosomes of various individuals. In general use, the phrase "genetic makeup" is sometimes used conversationally to mean the genome of a particular individual or organism. The study of the global properties of genomes of related organisms is usually referred to as genomics, which distinguishes it from genetics which generally studies the properties of single genes or groups of genes.
Types of genomes

Most biological entities more complex than a virus sometimes or always carry additional genetic material besides that which resides in their chromosomes. In some contexts, such as sequencing the genome of a pathogenic microbe, "genome" is meant to include this auxiliary material, which is carried in plasmids. In such circumstances then, "genome" describes all of the genes and non-coding DNA that have the potential to be present.

In vertebrates such as humans, however, "genome" carries the typical connotation of only chromosomal DNA. So although human mitochondria contain genes, these genes are not considered part of the genome. In fact, mitochondria are sometimes said to have their own genome, often referred to as the "mitochondrial genome".

Genomes and genetic variation

Note that a genome does not capture the genetic diversity or the genetic polymorphism of a species. For example, the human genome sequence in principle could be determined from just half the DNA of one cell from one individual. To learn what variations in DNA underlie particular traits or diseases requires comparisons across individuals. This point explains the common usage of "genome" (which parallels a common usage of "gene") to refer not to any particular DNA sequence, but to a whole family of sequences that share a biological context.

Although this concept may seem counter intuitive, it is the same concept that says there is no particular shape that is the shape of a cheetah. Cheetahs vary, and so do the sequences of their genomes. Yet both the individual animals and their sequences share commonalities, so one can learn something about cheetahs and "cheetah-ness" from a single example of either.

Minimal genomes

Since genomes and their organisms are very complex, one research strategy is to reduce the number of genes in a genome to the bare minimum and still have the organism in question survive. There is experimental work being done on minimal genomes for single cell organisms as well as minimal genomes for multicellular organisms (see Developmental biology). The work is both in vivo and in silico. By understanding the functioning of minimal organisms one hopes to add complexity incrementally leading to the understanding of multicellular diseases such as Cancer.

Genome projects

The Human Genome Project was organized to map and to sequence the human genome. Other genome projects include mouse, rice, the plant Arabidopsis thaliana, the puffer fish, bacteria like E. coli, etc. The first genome project to be completed was the Phage Φ-X174, with only 5368 base pairs, which was sequenced by Fred Sanger in 1982. The first bacterial genome to be completed was that of Haemophilus influenzae, completed by a team at The Institute for Genomic Research in 1995. Many genomes have been sequenced by various genome projects. The cost of sequencing continues to drop, and it is possible that eventually an individual human genome could be sequenced for around several thousand dollars (US).


Comparison of different genome sizes

For an updated list of sequenced genomes and their sizes, visit the Genomes OnLine Database (GOLD)
Organism Genome size (base pairs)
Virus, Phage Φ-X174; 5386 - First sequenced genome
Virus, Phage λ 5×104
Archaeum, Nanoarchaeum equitans 5×105 - Smallest non-viral genome Dec, 2005
Bacterium, Buchnera aphidicola 6×105
Bacterium, Wigglesworthia glossinidia 7×105
Bacterium, Escherichia coli 4×106
Amoeba, Amoeba dubia 6.7×1011 - Largest known genome Dec, 2005
Plant, Arabidopsis thaliana 1.2×108 - First plant genome sequenced, Dec 2000
Plant, Fritillaria assyrica 1.3×1011
Plant, Populus trichocarpa 4.8×108 - First tree genome, Sept 2006
Fungus,Saccharomyces cerevisiae 2×107
Nematode, Caenorhabditis elegans 8×107
Insect, Drosophila melanogaster 1.3×108
Mammal, Homo sapiens 3×109

Genome evolution

Genomes are more than the sum of an organism's genes and have traits that may be measured and studied without reference to the details of any particular genes and their products. Researchers compare traits such as chromosome number (karyotype), genome size, gene order, codon usage bias, and GC-content to determine what mechanisms could have produced the great variety of genomes that exist today (for recent overviews, see Brown 2002; Saccone and Pesole 2003; Benfey and Protopapas 2004; Gibson and Muse 2004; Reese 2004; Gregory 2005).

Duplications play a major role in shaping the genome. Duplications may range from extension of short tandem repeats, to duplication of a cluster of genes, and all the way to duplications of entire chromosomes or even entire genomes. Such duplications are probably fundamental to the creation of genetic novelty.

Horizontal gene transfer is invoked to explain how there is often extreme similarity between small portions of the genomes of two organisms that are otherwise very distantly related. Horizontal gene transfer seems to be common among many microbes. Also, eukaryotic cells seem to have experienced a transfer of some genetic material from their chloroplast and mitochondrial genomes to their nuclear chromosomes.

2006-09-16 07:22:32 · answer #6 · answered by PK LAMBA 6 · 0 0

All the DNA products in a cell.

2006-09-16 08:10:45 · answer #7 · answered by Anonymous · 0 0

visit http://en.wikipedia.org/wiki/Genome

2006-09-16 07:03:29 · answer #8 · answered by Gnanu 2 · 0 0

All DNA in our cell

2006-09-16 23:45:53 · answer #9 · answered by chanseypokemon 2 · 0 0

its a gene which has the rna and dna on it

2006-09-17 01:45:40 · answer #10 · answered by weirdoonee 4 · 0 0

fedest.com, questions and answers