Sebopeho sa Chromosome ka har'a Nucleus ea Eukaryotic
Li-chromosome ke meaho e rarahaneng e fumanehang ka har'a khubu ea lisele tsa eukaryotic. Li bapala karolo ea bohlokoa polokelong, ho ikatiseng le ho hlahisoeng ha tlhahisoleseling ea liphatsa tsa lefutso. Sehloohong sena, re tla hlahloba sebopeho sa li-chromosome tsa eukaryotic ka botebo, re utloisise likarolo tsa tsona tsa motheo, mekhoa ea ho hlophisa, le bohlokoa ba tsona moelelong oa baeloji ea sele le ea limolek'hule.
Selelekela: Chromosome ke eng?
Li-chromosome ke meaho e bōpehileng joaloka molamu e entsoeng ka DNA le liprotheine. Liseleng tsa eukaryotic, li-chromosome li fumaneha ka har'a nucleus. Sele ea motho, mohlala, e na le li-chromosome tse 46, tse nang le lipara tse 23 tsa li-chromosome tse tšoanang.
Sebopeho sa Motheo sa Li-chromosome
1. DNA: Karolo ea bohlokoa ka ho fetisisa ea chromosome ke DNA (deoxyribonucleic acid). DNA ke molek'hule e telele ea polymer e bolokang tlhahisoleseling ea liphatsa tsa lefutso. Molek'hule e 'ngoe le e 'ngoe ea DNA ka har'a chromosome e kobehile 'me e hatelloa ho ba sebopeho se kopaneng haholoanyane ka thuso ea liprotheine.
2. Li-Histone: Liprotheine tsa Histone ke liprotheine tse kopanyang sebopeho tse bapalang karolo ea bohlokoa ho hlophiseng DNA. DNA e phuthetsoe ho potoloha likhoele tsa histone, e leng se etsang meaho e bitsoang li-nucleosome. Nucleosome e na le lipara tse ka bang 147 tsa motheo tsa DNA tse phuthetsoeng ho potoloha karolo ea mantlha ea liprotheine tse robeli tsa histone (histone octamer).
3. Chromatin: Motswako wa diprotheine tsa DNA le histone o bitswa chromatin. Chromatin e ka hlaha ka mefuta e mmedi:
– Euchromatin: Sebaka se hlephileng, se sebetsang ka mokhoa oa ho ngola, se lumellang lienzyme tsa ho ngola le lintlha tse ling ho fihlella DNA.
– Heterochromatin: Libaka tse teteaneng haholo le tse sa sebetseng haholo ho ngoleng, tse tšoanang le liphatsa tsa lefutso tse sa hlokeheng ke sele maemong a itseng.
Sephutheloana sa Chromosome: Ho tloha ho DNA ho ea ho Chromosome
DNA e telele ea eukaryotic e hloka ho khutsufatsoa hore e lekane le khubu ea sele e nyane. Ts'ebetso ena e kenyelletsa maemo a 'maloa a tlhophiso:
1. Nucleosomes: Boemo ba pele ba tlhophiso bo boletsoeng pejana. Nucleosomes li thusa ho fokotsa bolelele ba DNA e fihlellehang ka ho e phuthela ka likaroloana tse kang lifaha.
2. Lifaeba tsa 30 nm: Li-nucleosome li mennoa hape hore e be lifaeba tsa chromatin tse bophara ba hoo e ka bang 30 nm. Sena se fana ka ho thatafala ho eketsehileng bakeng sa DNA 'me se ka feta ho kobeha ho eketsehileng mehatong e itseng, joalo ka nakong ea karohano ea sele.
3. Libaka tse Loheletsoeng: Likhoele tsena tsa 30 nm li kopanngoa ka li-loop tse tlameletsoeng lesapo la mokokotlo la protheine, li etsa sebopeho se teteaneng haholoanyane. Li-loop tsena li ka hlophisoa haholoanyane ka libopeho tse phahameng.
4. Ho Koaleha ha Chromosome: Nakong ea mitosis kapa meiosis ea karohano ea sele, li-chromosome li ntse li hola ho fihlela li ka bonoa ka tlas'a microscope e khanyang. Ena ke boemo bo phahameng ka ho fetisisa ba ho hoaleha, ho netefatsa kabo e nepahetseng ea tlhahisoleseling ea lefutso ho lisele tsa morali.
Karolo e Sebetsang le Bohlokoa ba Sebopeho sa Chromosome
1. Ho Ikatisa ha DNA: Sebopeho sa di-chromosome se dumella ho ikatisa ha DNA ka nepo le ka katleho pele ho karohano ya sele. Chromosome ka nngwe e feta ho ikatisa e le hore sele e nngwe le e nngwe ya moradi e fumane sete e felletseng ya di-chromosome.
2. Phetolelo ea DNA: Boteng ba euchromatin e lokolohileng bo lumella tlhahiso ea liphatsa tsa lefutso tse hlokahalang bakeng sa ts'ebetso ea sele, ha mokhatlo oa heterochromatin o boloka liphatsa tsa lefutso li sa sebetse tlas'a maemo a itseng.
3. Kabo ea Liphatsa tsa Lefutso Nakong ea Karohano: Ho kobeha ha chromosome nakong ea mitosis le meiosis ho netefatsa hore sele e 'ngoe le e 'ngoe e fumana sete e felletseng ea li-chromosome, e leng sa bohlokoa bakeng sa kholo, ho ikatisa le ho lokisa lisele.
4. Taolo ea Liphatsa tsa Lefutso: Tsela eo DNA e phuthetsoeng ka har'a li-nucleosome e ama bokhoni ba liphatsa tsa lefutso ba ho hlahisoa. Liphetoho tsa lik'hemik'hale ho li-histone le DNA, tse kang methylation le acetylation, li ka fetola phihlello ea libaka tse itseng tsa DNA, e leng mokhoa oa bohlokoa oa taolo ea liphatsa tsa lefutso.
Sebopeho le Mafu a Chromosome
Mathata sebopehong kapa palong ea li-chromosome a ka baka mafu a liphatsa tsa lefutso. Maemo a mang a tsebahalang a kenyelletsa:
1. Down Syndrome: E bakoa ke kopi e eketsehileng ea chromosome 21 (trisomy 21).
2. Kankere: Liphetoho sebopehong sa chromosome, tse kang ho falla ha lisele kapa ho holisa liphatsa tsa lefutso, li ka kenya tšebetsong li-oncogene kapa tsa tima liphatsa tsa lefutso tse hatellang hlahala.
3. Lefu la Klinefelter: Le tšoauoa ka ho feta chromosome e le 'ngoe kapa ho feta ea X ho banna.
4. Turner Syndrome: E bakoa ke monosomy X, moo mosali a nang le chromosome e le 'ngoe feela ea X.
Lipatlisiso tsa Nakong e Tlang Tšimong ea Li-Chromosomes
Phuputso e eketsehileng mabapi le sebopeho le mosebetsi oa chromosome e batla ho fana ka leseli le eketsehileng ka mafu a liphatsa tsa lefutso le kankere, hammoho le ho fumana litsela tsa ho nts'etsapele mekhoa e mecha ea phekolo. Mohlala, ho utloisisa karolo ea liphetoho tsa hysteresis taolong ea liphatsa tsa lefutso ho butse litsela tse ncha bakeng sa nts'etsopele ea meriana e ka fetolang kapa ea shebana le liphetoho tsena ho phekola lefu.
Qetello
Sebopeho sa di-chromosome ka hara nucleus ya eukaryotic ke moralo o rarahaneng empa o hlophisitswe o netefatsang polokelo e nepahetseng, tlhahiso le phetiso ya tlhahisoleseding ya lefutso. Di-chromosome ha se feela dihlopha tsa DNA; ke disebediswa tse nepahetseng bakeng sa bophelo, tse bontshang tekano e phethahetseng pakeng tsa botsitso ba lefutso le ho tenyetseha. Ka ho utlwisisa di-chromosome, ha re notlolle diphiri tsa bophelo feela empa hape re bula tsela bakeng sa kgatelopele ya bongaka le ya biotechnology nakong e tlang.
