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Both the number of base pairs and the number of genes vary widely from one species to another, and there is little connection between the two (an observation known as the C-value paradox ). At present, the highest known number of genes is around 60,000, for the protozoan causing trichomoniasis (see List of sequenced eukaryotic genomes ), almost three times as many as in the human genome .

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 information on the DNA of one cell from one individual. To learn what variations in genetic information 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 the information in 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.

Comparison of different genome sizes

Organism Genome size ( base pairs ) Note
Virus , Bacteriophage MS2 3,569 First sequenced RNA-genome [3]
Virus , SV40 5,224 [4]
Virus , Phage Φ-X174; 5,386 First sequenced DNA-genome [5]
Virus , Phage λ 48,502
Bacterium , Haemophilus influenzae 1,830,000 First genome of living organism, July 1995 [6]
Bacterium , Carsonella ruddii 160,000 Smallest non-viral genome. [7]
Bacterium , Buchnera aphidicola 600,000
Bacterium , Wigglesworthia glossinidia 700,000
Bacterium , Escherichia coli 4,600,000 [8]
Amoeba , Amoeba dubia 670,000,000,000 Largest known genome. [9]
Plant , Arabidopsis thaliana 157,000,000 First plant genome sequenced, Dec 2000. [10]
Plant , Genlisea margaretae 63,400,000 Smallest recorded flowering plant genome, 2006. [10]
Plant , Fritillaria assyrica 130,000,000,000
Plant , Populus trichocarpa 480,000,000 First tree genome, Sept 2006
moss , Physcomitrella patens 480,000,000 First genome of a bryophyte , January 2008 [11]
Yeast , Saccharomyces cerevisiae 12,100,000 [12]
Fungus , Aspergillus nidulans 30,000,000
Nematode , Caenorhabditis elegans 98,000,000 First multicellular animal genome, December 1998 [13]
Insect , Drosophila melanogaster aka Fruit Fly 130,000,000 [14]
Insect , Bombyx mori aka Silk Moth 530,000,000
Insect , Apis mellifera aka Honey Bee 1,770,000,000
Fish , Tetraodon nigroviridis , type of Puffer fish 385,000,000 Smallest vertebrate genome known
Mammal , Homo sapiens 3,200,000,000
Fish , Protopterus aethiopicus aka Marbled lungfish 130,000,000,000 Largest vertebrate genome known

Lecture 13. living organisms share common genes

All organisms store genetic information in the same molecules - DNA or RNA. Written in the genetic code of these molecules is compelling evidence of the shared ancestry of all living things. Evolution of higher life forms requires the development of new genes to support different body plans and types of nutrition. Even so, complex organisms retain many genes that govern core metabolic functions carried over from their primitive past.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Genetics. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10782/1.1
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