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Investigation of the tenacity and versatility of life on Earth,<ref name="NYT-20160912"/> as well as an understanding of the molecular systems that some organisms utilize to survive such extremes, is important for the search for [[extraterrestrial life|life beyond Earth]].<ref name=astrobiology/> For example, [[lichen]] could survive for a month in a [[Life on Earth under Martian conditions|simulated Martian environment]].<ref name="Skymania-20120426">{{cite web |last=Baldwin |first=Emily |title=Lichen survives harsh Mars environment |url=http://www.skymania.com/wp/2012/04/lichen-survives-harsh-martian-setting.html |date=26 April 2012 |publisher=Skymania News |accessdate=27 April 2012 }}</ref><ref name="EGU-20120426">{{cite web |last1=de Vera |first1=J.-P. |last2=Kohler |first2=Ulrich |title=The adaptation potential of extremophiles to Martian surface conditions and its implication for the habitability of Mars |url=http://media.egu2012.eu/media/filer_public/2012/04/05/10_solarsystem_devera.pdf |archiveurl=https://www.webcitation.org/68GROCilv?url=http://media.egu2012.eu/media/filer_public/2012/04/05/10_solarsystem_devera.pdf |archivedate=8 June 2012 |date=26 April 2012 |publisher=[[European Geosciences Union]] |accessdate=27 April 2012 }}</ref>
===রাসায়নিক উপাদান===
Allসকল lifeজীবিত forms require certain coreবস্তুর [[chemical elementপ্রাণরসায়ন|জৈবরাসায়নিক]]s neededকার্যকলাপ forচলানোর জন্য কিছু মূল [[biochemistry|biochemicalরাসায়নিক উপাদান]] functioning. These includeপ্রয়োজন। [[carbonকার্বন]], [[hydrogenহাইড্রোজেন]], [[nitrogenনাইট্রোজেন]], oxygen, [[phosphorusঅক্সিজেন]], and [[sulfurফসফরাস]]—the, elementalএবং [[nutrientগন্ধক|macronutrientsসালফার]]- forএগুলো allহল organisms<refসব name=wsj20101203>{{citeপ্রাণীর newsজন্য | first1=Robert Leeমৌলিক [[পুষ্টি|ম্যাক্রোনিউট্রিয়েন্ট]] last1=Hotz- |এগুলোকে title=Newপ্রায়ই linkইংরেজি inআদ্যক্ষর chain of life | work=[[Wall Street Journalসিএইচওএন|সিএইচএনওপিএস]] |দ্বারা date=3প্রকাশ Decemberকরা 2010হয়। |একসঙ্গে publisher=Dowএগুলো Jonesবেঁচে &থাকার Company,মৌলিক Incবস্তু | url=https://www.wsj.com/articles/SB10001424052748703377504575650840897300342?mod=ITP_pageone_1#printMode[[নিউক্লিক এসিড|নিউক্লিক quote="Until now, however, they were all thought to share the same biochemistry, based on the Big Six, to build proteins, fats and DNA." }}</ref>—often represented by the acronym [[CHNOPSঅ্যাসিড]]. Together these make up, [[nucleic acidপ্রোটিন]]s, proteins andএবং [[lipidলিপিড]]s, theতৈরি bulkকরে। of living matter.এই Fiveছয়টি ofউপাদানগুলির theseমধ্যে sixপাঁচটি elementsদ্বারা compriseডিএনএর the chemicalরাসায়নিক componentsউপাদানগুলি ofগঠিত DNAহয়, theএকমাত্র exceptionব্যতিক্রম beingহচ্ছে sulfur.সালফার। The latter is a component of theপরেরটি aminoঅ্যামিনো acidsঅ্যাসিডের [[cysteineসিসটেইন]] andএবং [[methionineম্যাথিয়োনাইন]]. Theগঠনের mostএকটি biologicallyউপাদান। abundantএই ofউপাদানের theseমধ্যে elementsজৈবিকভাবে isসবচেয়ে carbon,বেশি whichপ্রচুর্য hasরয়েছে the desirable attributeকার্বনের, ofযা forming multipleএকাধিক, stableস্থিতিশীল [[covalentসমযোজী bondবন্ধন|সমযোজী বন্ধনী]]s. Thisগঠনের জন্য প্রয়োজনীয় বৈশিষ্ট্য রয়েছে। allowsযা carbonকার্বন-basedভিত্তিক (organicজৈব) moleculesঅণুর toবিভিন্ন formধরণের anরাসায়নিক immenseগঠন varietyতৈরি ofকরতে chemicalসহায়তা arrangements.করে।<ref name=neuhauss2005>{{Cite book | first1=Scott | last1=Neuhaus | title=Handbook for the Deep Ecologist: What Everyone Should Know About Self, the Environment, And the Planet | publisher=iUniverse | date=2005 | isbn=978-0-521-83113-0 | pages=23–50 | url=https://books.google.com/books?id=uzBDQPxe6zsC&pg=PA23}}</ref> Alternativeবিকল্প [[hypotheticalকাল্পনিক typesধরণের ofপ্রাণরসায়ন|কাল্পনিক ধরণের biochemistryজৈবরাসায়নিক]] haveব্যবস্থার beenপ্রস্তাব proposedকরা thatহয়েছে eliminateযা oneএগুলোর orএক moreবা ofএকাধিক theseউপাদানকে elementsবাদ দেয়, swapকিংবা outতালিকার anকোনও elementএকটি forউপাদানকে oneঅদলবদল notকরে onবাইরের theকোন listউপাদান দ্বারা, or change requiredবা [[Chiralityকাইরালিটি (chemistryরসায়ন)|chiralitiesকাইরালিটির]] orপ্রয়োজনীয় otherপরিবর্তন chemicalকরে properties.বা অন্যান্য রাসায়নিক বৈশিষ্ট্যগুলি পরিবর্তন করে।<ref>{{cite book | author1=Committee on the Limits of Organic Life in Planetary Systems | author2=Committee on the Origins and Evolution of Life | author3=National Research Council | date=2007 | publisher=National Academy of Sciences | title=The Limits of Organic Life in Planetary Systems | isbn=0-309-66906-5 | url=http://www.nap.edu/catalog.php?record_id=11919 | accessdate=3 June 2012 }}</ref><ref>{{cite journal | first1=Steven A. | last1=Benner | first2=Alonso | last2=Ricardo | first3=Matthew A. | last3=Carrigan | journal=Current Opinion in Chemical Biology | title=Is there a common chemical model for life in the universe? | volume=8 | issue=6 |date=December 2004 | pages=672–89 | doi=10.1016/j.cbpa.2004.10.003 | url=http://www.fossildna.com/articles/benner_commonmodelforlife.pdf | archiveurl=https://www.webcitation.org/68GROD92N?url=http://www.fossildna.com/articles/benner_commonmodelforlife.pdf | archivedate=8 June 2012 | accessdate=3 June 2012 | pmid=15556414}}</ref>
====ডিএনএ====
{{Mainমূল articleনিবন্ধ|ডিএনএ}}
Deoxyribonucleic acid is a [[molecule]] that carries most of the [[genetics|genetic]] instructions used in the growth, development, functioning and [[reproduction]] of all known living [[organism]]s and many [[virus]]esviruses. DNA and [[RNA]] are [[nucleic acid]]<nowiki/>s; alongside [[protein]]s and [[Polysaccharide|complex carbohydrates]], they are one of the three major types of [[macromolecules|macromolecule]] that are essential for all known forms of life. Most DNA molecules consist of two [[biopolymer]] strands coiled around each other to form a [[Nucleic acid double helix|double helix]]. The two DNA strands are known as [[polynucleotide]]s since they are composed of [[monomer|simpler units]] called [[nucleotide]]s.<ref>{{cite web |url=http://basicbiology.net/micro/genetics/dna |title=DNA |date=5 February 2016 |website=Basic Biology |publisher= |access-date=15 November 2016 |last1=Purcell |first1=Adam |deadurl=no |archiveurl=https://web.archive.org/web/20170105045651/http://basicbiology.net/micro/genetics/dna/ |archivedate=5 January 2017 |df=dmy-all }}</ref> Each nucleotide is composed of a [[nitrogenous base|nitrogen-containing]] [[nucleobase]]—either [[cytosine]] (C), [[guanine]] (G), [[adenine]] (A), or [[thymine]] (T)—as well as a [[monosaccharide|sugar]] called [[deoxyribose]] and a [[phosphate group]]. The nucleotides are joined to one another in a chain by [[covalent bond]]s between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating [[backbone chain|sugar-phosphate backbone]]. According to [[base pair]]ing rules (A with T, and C with G), [[hydrogen bond]]s bind the nitrogenous bases of the two separate polynucleotide strands to make double-stranded DNA. The total amount of related DNA [[base pair]]s on Earth is estimated at 5.0 x 10<sup>37</sup>, and weighs 50 billion [[tonne]]s.<ref name="NYT-20150718-rn">{{cite news |last=Nuwer |first=Rachel |date=18 July 2015 |title=Counting All the DNA on Earth |url=https://www.nytimes.com/2015/07/21/science/counting-all-the-dna-on-earth.html |work=The New York Times |location=New York |publisher=The New York Times Company |issn=0362-4331 |accessdate=2015-07-18 |deadurl=no |archiveurl=https://web.archive.org/web/20150718153742/http://www.nytimes.com/2015/07/21/science/counting-all-the-dna-on-earth.html |archivedate=18 July 2015 |df=dmy-all }}</ref><!--- PLOS paper cited by NYT used 'tonne' unit. ---><!-- In comparison, the total [[Biomass (ecology)|mass]] of the [[biosphere]] has been estimated to be as much as 4 [[tonnes#Derived units|TtC]] (trillion tons of [[carbon]]).<ref name="AGCI-2015">{{cite web |url=http://www.agci.org/classroom/biosphere/index.php |title=The Biosphere: Diversity of Life |author=<!--Staff writer(s); no by-line.--><!--- |work=Aspen Global Change Institute |location=Basalt, CO |accessdate=2015-07-19}}</ref><!--- Aspen Global Change Institute (US-based) defined TtC as 'trillion tons of C'. ---><!--
DNA stores biological [[information]]. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information. Biological information is replicated as the two strands are separated. A significant portion of DNA (more than 98% for humans) is [[non-coding DNA|non-coding]], meaning that these sections do not serve as patterns for protein sequences.
The two strands of DNA run in opposite directions to each other and are therefore [[antiparallel (biochemistry)|anti-parallel]]. Attached to each sugar is one of four types of nucleobases (informally, ''bases''). It is the [[Nucleic acid sequence|sequence]] of these four nucleobases along the backbone that encodes biological information. Under the [[genetic code]], [[RNA]] strands are translated to specify the sequence of [[amino acid]]s within proteins. These RNA strands are initially created using DNA strands as a template in a process called [[transcription (genetics)|transcription]].
Within cells, DNA is organized into long structures called [[chromosome]]s. During [[cell division]] these chromosomes are duplicated in the process of [[DNA replication]], providing each cell its own complete set of chromosomes. [[Eukaryote|Eukaryotic organisms]] ([[animal]]sanimals, [[plant]]splants, [[Fungus|fungi]], and [[protist]]s) store most of their DNA inside the [[cell nucleus]] and some of their DNA in [[organelle]]s, such as [[mitochondria]] or [[chloroplasts]].<ref>{{cite book | last = Russell | first = Peter | title = iGenetics | publisher = Benjamin Cummings | location = New York | year = 2001 | isbn = 0-8053-4553-1 }}</ref> In contrast, [[prokaryote]]s ([[bacteria]] and [[archaea]]) store their DNA only in the [[cytoplasm]]. Within the chromosomes, [[chromatin]] proteins such as [[histone]]s compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
DNA was first isolated by [[Friedrich Miescher]] in 1869.<ref>{{cite journal | author = Dahm R | title = Discovering DNA: Friedrich Miescher and the early years of nucleic acid research | journal = Hum. Genet. | volume = 122 | issue = 6 | pages = 565–81 | year = 2008 | pmid = 17901982 | doi = 10.1007/s00439-007-0433-0 }}</ref> Its molecular structure was identified by [[James Watson]] and [[Francis Crick]] in 1953, whose model-building efforts were guided by [[X-ray diffraction]] data acquired by [[Rosalind Franklin]].<ref name="pmid24840850">{{cite journal |vauthors=Portin P |title=The birth and development of the DNA theory of inheritance: sixty years since the discovery of the structure of DNA |journal=Journal of Genetics |volume=93 |issue=1 |pages=293–302 |year=2014 |pmid=24840850 |doi= 10.1007/s12041-014-0337-4 |url=}}</ref> ▼
▲DNA was first isolated by [[Friedrich Miescher]] in 1869.<ref>{{cite journal | author = Dahm R | title = Discovering DNA: Friedrich Miescher and the early years of nucleic acid research | journal = Hum. Genet. | volume = 122 | issue = 6 | pages = 565–81 | year = 2008 | pmid = 17901982 | doi = 10.1007/s00439-007-0433-0 }}</ref> Its molecular structure was identified by [[James Watson]] and [[Francis Crick]] in 1953, whose model-building efforts were guided by [[X-ray diffraction]] data acquired by [[Rosalind Franklin]].<ref name="pmid24840850">{{cite journal |vauthors=Portin P |title=The birth and development of the DNA theory of inheritance: sixty years since the discovery of the structure of DNA |journal=Journal of Genetics |volume=93 |issue=1 |pages=293–302 |year=2014 |pmid=24840850 |doi= 10.1007/s12041-014-0337-4|url=}}</ref>
==শ্রেণীবিন্যাস==
[[বিষয়শ্রেণী:প্রকৃতি]]
[[বিষয়শ্রেণী:জীববিজ্ঞান]]
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