Variability hauv biology yog qhov tshwm sim ntawm tus kheej qhov sib txawv ntawm cov tib neeg ntawm tib hom. Vim muaj qhov sib txawv, cov pej xeem ua ntau yam, thiab cov hom muaj qhov zoo dua ntawm kev hloov mus rau kev hloov ib puag ncig.
Nyob hauv kev tshawb fawb xws li biology, heredity thiab variation mus sib koom tes. Muaj ob hom kev hloov pauv:
- Tsis yog-kev hloov pauv, phenotypic).
- Hereditary (mutational, genotypic).
Ntxhais kab mob sib txawv
Kev hloov pauv hloov pauv hauv biology yog lub peev xwm ntawm tib lub cev muaj sia (phenotype) hloov mus rau ib puag ncig yam hauv nws cov genotype. Vim yog cov cuab yeej no, cov tib neeg hloov mus rau kev hloov pauv hauv huab cua thiab lwm yam kev muaj nyob. Phenotypic variability underlies lub adaptive txheej txheem tshwm sim nyob rau hauv tej yam kab mob. Yog li ntawd, nyob rau hauv outbred tsiaj, nrog rau kev txhim kho ntawm tej yam kev mob ntawm kev kaw, productivity nce: mis nyuj tawm los, qe ntau lawm, thiab hais txog. Thiab cov tsiaj coj mus rau thaj tsam roob loj hlob luv thiab muaj kev noj qab haus huv.tsim undercoat. Kev hloov ntawm ib puag ncig yam thiab ua rau muaj kev hloov pauv. Piv txwv ntawm cov txheej txheem no tuaj yeem pom tau yooj yim hauv lub neej txhua hnub: tib neeg cov tawv nqaij yuav tsaus ntuj nyob rau hauv kev cuam tshuam ntawm ultraviolet rays, cov nqaij ntshiv tshwm sim los ntawm kev siv lub cev, cov nroj tsuag loj hlob hauv qhov chaw ntxoov ntxoo thiab nyob rau hauv lub teeb muaj cov nplooj sib txawv, thiab hares hloov lub tsho loj. xim nyob rau lub caij ntuj no thiab lub caij ntuj sov.
Cov khoom hauv qab no yog cov yam ntxwv ntawm kev hloov pauv tsis yog keeb kwm:
- pawg xwm ntawm kev hloov;
- tsis tau xeeb leej xeeb ntxwv;
- hloov tus cwj pwm hauv genotype;
- Qhov piv ntawm qib kev hloov pauv nrog kev siv zog ntawm qhov cuam tshuam ntawm lwm yam.
Hereditary variability
Hereditary lossis genotypic variability hauv biology yog cov txheej txheem uas cov genome ntawm cov kab mob hloov pauv. Ua tsaug rau nws, tus neeg tau txais cov yam ntxwv uas yav tas los txawv txawv rau nws hom. Raws li Darwin, genotypic variation yog lub ntsiab cav ntawm evolution. Muaj cov nram qab no hom kev hloov pauv hloov pauv:
- mutational;
- kev sib hlub.
Kev sib txuam sib txawv tau tshwm sim los ntawm kev sib pauv ntawm cov noob thaum muaj kev sib deev. Nyob rau tib lub sijhawm, cov yam ntxwv ntawm cov niam txiv tau ua ke sib txawv hauv ntau tiam neeg, ua rau muaj kev sib txawv ntawm cov kab mob hauv cov pej xeem. Combinative variability ua raws cov cai ntawm Mendelian qub txeeg qub teg.
Ib qho piv txwv ntawm xws li kev sib txawv yog inbreeding thiab outbreeding (ze ze ze thiabinbreeding). Thaum cov yam ntxwv ntawm tus neeg tsim khoom xav tau kho nyob rau hauv cov tsiaj yug tsiaj, ces inbreeding yog siv. Yog li, cov xeeb ntxwv ua ntau yam sib xws thiab txhawb nqa qhov zoo ntawm tus tsim ntawm kab. Inbreeding ua rau qhov tshwm sim ntawm recessive noob thiab tuaj yeem ua rau degeneration ntawm kab. Txhawm rau kom muaj kev vam meej ntawm cov xeeb ntxwv, kev yug me nyuam yog siv - kev hla tsis sib xws. Nyob rau tib lub sijhawm, heterozygosity ntawm cov xeeb ntxwv nce thiab ntau haiv neeg hauv cov pej xeem nce, thiab, vim li ntawd, kev tawm tsam ntawm tib neeg rau qhov tsis zoo ntawm ib puag ncig yam tseem ceeb nce.
Mutations, tig, muab faib ua:
- genomic;
- chromosomal;
- genetic;
- cytoplasmic.
Txoj kev hloov pauv cuam tshuam rau kev sib deev hlwb tau txais los. Kev hloov pauv hauv cov hlwb somatic tuaj yeem kis mus rau cov xeeb ntxwv yog tias ib tus neeg rov tsim dua vegetatively (nroj tsuag, fungi). Kev hloov pauv tuaj yeem muaj txiaj ntsig, nruab nrab lossis tsim kev puas tsuaj.
Genomic mutations
Variability hauv biology los ntawm kev hloov genomic tuaj yeem yog ob hom:
- Polyploidy - kev hloov pauv muaj nyob hauv cov nroj tsuag. Nws yog tshwm sim los ntawm ntau qhov nce ntawm tag nrho cov chromosomes nyob rau hauv lub nucleus, yog tsim nyob rau hauv tus txheej txheem ntawm kev ua txhaum ntawm lawv divergence rau cov ncej ntawm lub cell thaum lub sij hawm faib. Polyploid hybrids tau siv dav hauv kev ua liaj ua teb - hauv kev tsim qoob loo muaj ntau tshaj 500 polyploids (dos, buckwheat, qab zib beet, radish, mint, txiv hmab txiv ntoo thiab lwm yam).
- Aneuploidy -nce lossis txo tus naj npawb ntawm chromosomes hauv ib tus khub. Hom kev hloov pauv no yog yam ntxwv los ntawm kev muaj peev xwm tsawg ntawm tus neeg. Kev hloov pauv thoob plaws hauv tib neeg - ib qho ntxiv chromosome ntawm 21 khub ua rau Down syndrome.
Chromosomal mutations
Variability hauv biology los ntawm chromosomal mutations tshwm sim thaum cov qauv ntawm chromosomes lawv tus kheej hloov: poob ntawm qhov kawg seem, rov ua dua ntawm cov noob caj noob ces, kev sib hloov ntawm ib feem, hloov ntawm chromosome ntu mus rau lwm qhov chaw lossis mus rau lwm chromosome. Cov kev hloov pauv no feem ntau tshwm sim nyob rau hauv kev cuam tshuam ntawm hluav taws xob thiab tshuaj lom neeg ib puag ncig.
Gene mutations
Ib feem tseem ceeb ntawm cov kev hloov pauv no tsis tshwm sim sab nraud, vim tias nws yog qhov tsis zoo. Gene mutations yog tshwm sim los ntawm kev hloov pauv hauv cov kab ke ntawm nucleotides - tib neeg cov noob - thiab ua rau pom cov protein molecules nrog cov khoom tshiab.
Gene mutations nyob rau hauv tib neeg ua rau tshwm sim ntawm qee yam kab mob - kab mob ntawm tes anemia, hemophilia.
YCytoplasmic mutations
Cytoplasmic mutations yog txuam nrog kev hloov hauv cov qauv ntawm cov cell cytoplasm uas muaj DNA molecules. Cov no yog mitochondria thiab plastids. Xws li kev hloov pauv yog kis los ntawm leej niam kab, txij li lub zygote tau txais tag nrho cov cytoplasm los ntawm niam lub qe. Ib qho piv txwv ntawm kev hloov cytoplasmic uas tau ua rau muaj kev hloov pauv hauv biology yog cog pinnateness, uas yog tshwm sim los ntawm kev hloov pauv.hauv chloroplasts.
Txhua qhov kev hloov pauv muaj cov khoom nram qab no:
- Lawv tshwm tam sim ntawd.
- Handed down.
- Lawv tsis muaj kev taw qhia. Kev hloov pauv tuaj yeem dhau los ntawm thaj chaw tsis tseem ceeb thiab lub cim tseem ceeb.
- Ua rau tus kheej, uas yog, tus kheej.
- Nyob rau hauv lawv qhov tshwm sim, kev hloov pauv tuaj yeem rov ua dua lossis tseem ceeb.
- Kev hloov pauv qub tuaj yeem rov ua dua.
Txhua qhov kev hloov pauv yog tshwm sim los ntawm qee qhov laj thawj. Feem ntau, nws tsis tuaj yeem txiav txim siab kom raug. Raws li kev sim, kom tau txais kev hloov pauv, ib qho kev qhia ntawm ib puag ncig sab nraud yog siv - hluav taws xob raug thiab lwm yam.
