Cov txheej txheem:
Video: Dab tsi ua rau muaj qhov hloov pauv hloov pauv?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Point kev hloov . Point kev hloov , hloov nyob rau hauv ib tug noob nyob rau hauv uas ib tug hauv paus khub nyob rau hauv lub DNA ib theem zuj zus yog hloov. Point kev hloov pauv Feem ntau cov tshwm sim ntawm kev ua yuam kev thaum lub sij hawm DNA replication, txawm hais tias kev hloov kho ntawm DNA, xws li los ntawm raug rau X-rays los yog mus rau ultraviolet hluav taws xob, kuj yuav induce point kev hloov.
Hais txog qhov no, dab tsi yog 3 hom kev hloov pauv ntawm cov ntsiab lus?
Muaj peb hom DNA Mutations: lub hauv paus hloov, tshem tawm thiab ntxig
- Kev hloov pauv hauv paus. Ib qho kev hloov pauv yog hu ua point mutations, nco qab qhov kev hloov pauv ntawm Glu --- Val uas ua rau mob qog nqaij hlav.
- Kev tshem tawm.
- Insertions.
Qhov thib ob, puas yog kev tshem tawm ib qho kev hloov pauv? A kev hloov pauv tshwm sim thaum ib feem ntawm DNA molecule tsis tau theej thaum lub sij hawm DNA replication. Hauv ib point kev hloov ib qho yuam kev tshwm sim hauv ib qho nucleotide. Tag nrho lub hauv paus khub yuav ploj, lossis tsuas yog lub hauv paus nitrogenous ntawm tus tswv strand. Rau taw tes tshem tawm , ib tug nucleotide tau ua tshem tawm los ntawm cov kab ke.
Tib neeg kuj nug, dab tsi yog qhov kev hloov pauv nrog piv txwv?
Feem ntau cov proteins tuaj yeem tiv taus ib lossis ob point kev hloov ua ntej lawv txoj haujlwm hloov. Rau piv txwv , mob kab mob los ntawm ib leeg point kev hloov (ib tug missense kev hloov pauv ) hauv beta-hemoglobin noob uas hloov GAG codon rau hauv GUG, uas encodes cov amino acid valine es tsis yog glutamic acid.
Dab tsi yog ob hom kev hloov pauv ntawm cov ntsiab lus?
Muaj ob hom kev hloov pauv hloov pauv : puag hloov pauv thiab frameshift kev hloov pauv . Insertions thiab deletion yog hu ua frameshift kev hloov pauv vim tias lawv tsis tsuas yog cuam tshuam rau ib codon, peb lub hauv paus ib ntus uas codes rau ib qho amino acid, zoo li hauv kev hloov pauv.
Pom zoo:
Dab tsi yog qhov kev hloov pauv hloov pauv?
Kev hloov pauv, hauv molecular biology, yog hais txog kev hloov pauv hauv deoxyribonucleic acid (DNA), qhov twg ib qho (ob lub nplhaib) purine hloov pauv rau (ib lub nplhaib) pyrimidine, los yog vice versa
Dab tsi yog qhov txawv ntawm ib puag ncig kev hloov pauv thiab kev hloov pauv qub txeeg qub teg?
Qhov sib txawv ntawm cov yam ntxwv ntawm cov tib neeg ntawm tib hom yog hu ua variation. Qhov no yog inherited variation. Qee qhov kev hloov pauv yog qhov tshwm sim ntawm qhov sib txawv ntawm ib puag ncig, lossis ib tus neeg ua dab tsi. Qhov no yog hu ua environmental variation
Dab tsi yog qhov kev hloov pauv ntawm cov khoom uas txav ntawm qhov chaw mus rau qhov chaw ntawm - 12 m?
Kev piav qhia: Qhov kev txav ntawm ib qho khoom txav ntawm qhov chaw mus rau qhov chaw ntawm − 12 m yog 12 meters. Qhov kev ncua deb ntawm lub hauv paus chiv keeb mus rau qhov siab tshaj plaws txoj hauj lwm yog hu ua displacement ntawm ib yam khoom. Qhov siab tshaj plaws kev hloov pauv ntawm cov khoom nyob rau hauv ib nthwv dej yog hu ua crest thiab qhov tsawg kawg nkaus hloov pauv yog hu ua trough
Thaum ib qho kev sib cais ua rau muaj kev hloov pauv hloov pauv ntawm lub ntiaj teb nce ntxiv?
Txij li thaum lub kaw lus raug cais tawm, tsis muaj cua sov tuaj yeem khiav tawm (tus txheej txheem yog li adiabatic), yog li thaum lub zog ntws tawm hauv lub cev, qhov entropy ntawm qhov system nce, piv txwv li Δ Ssys> 0. Yog li ntawd, lub entropy ntawm lub system yuav tsum tau nce rau ib tug spontaneous txheej txheem nyob rau hauv no cais system
Peb qhov laj thawj tseem ceeb ntawm kev hloov pauv hloov pauv yog dab tsi?
Allele frequencies nyob rau hauv ib tug pej xeem yuav hloov vim plaub lub hauv paus zog ntawm evolution: Natural Selection, Genetic Drift, Mutations thiab Gene Flow. Kev hloov pauv yog qhov kawg ntawm cov alleles tshiab hauv cov noob caj noob ces. Ob ntawm cov txheej txheem tseem ceeb tshaj plaws ntawm kev hloov pauv hloov pauv yog: Natural Selection thiab Genetic Drift