01. Biologia mutaatiot ja mutageenit perinnöllisyys-genetiikka

Mutaatiot

helmi 23, 2019

Uutta ja ajankohtaista

BBC America; Julkaistu 13.2.2019

Perimä voi muuttua monella eri tavalla: Nettimateriaalia yleisesti

Netistä  (OpenStax- materiaali artikkelin lopussa)

Geenimutaatiot ja pistemutaatiot

Pistemutaation tapahtumatavat ja seuraukset; Download for free at http://cnx.org/contents/e42bd376-624b-4c0f-972f-e0c57998e765@6.1.; Creative Commons Attribution License 4.0 license.

Esimerkki:

Kromosomimutaatiot

De­le­ti­on;By Mir­mil­lon at fr.wiki­pe­dia [Pub­lic do­main], from Wi­ki­me­dia Com­mons

Kromosomistomutaatiot

  • yksittäistä kromosomia poikkeva määrä (ei siis 2)
Kromosomien epänormaali asettuminen meioosin I tai II keskivaiheessa johtaa sukusoluissa siihen, että yksi kromosomi puuttuu (n-1) tai samaa kromosomia on kolme (n+1); Download for free at http://cnx.org/contents/e42bd376-624b-4c0f-972f-e0c57998e765@6.1.; Creative Commons Attribution License 4.0 license.
Down Synd­ro­me Ka­ryo­ty­pe. from en: with same file name; By Cour­te­sy: Na­ti­o­nal Hu­man Ge­no­me Re­se­arch Ins­ti­tu­te (Hu­man Ge­no­me Pro­ject) [Pub­lic do­main], via Wi­ki­me­dia Com­mons

OpenStax- materiaali

OpenStax: mutaatiot
Intercalating agents, such as acridine, introduce atypical spacing between base pairs, resulting in DNA polymerase introducing either a deletion or an insertion, leading to a potential frameshift mutation.

Intercalating agents, such as acridine, introduce atypical spacing between base pairs, resulting in DNA polymerase introducing either a deletion or an insertion, leading to a potential frameshift mutation.

  

Ionizing radiation may lead to the formation of single-stranded and double-stranded breaks in the sugar-phosphate backbone of DNA,

Ionizing radiation may lead to the formation of single-stranded and double-stranded breaks in the sugar-phosphate backbone of DNA,

  

Bacteria have two mechanisms for repairing thymine dimers.

Bacteria have two mechanisms for repairing thymine dimers.

  

Identification of auxotrophic mutants, like histidine auxotrophs, is done using replica plating.

Identification of auxotrophic mutants, like histidine auxotrophs, is done using replica plating.

  

The Ames test is used to identify mutagenic, potentially carcinogenic chemicals.

The Ames test is used to identify mutagenic, potentially carcinogenic chemicals.

  

This karyotype is of a female human

This karyotype is of a female human

  

Nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis, resulting in an abnormal chromosome number. Nondisjunction may occur during meiosis I or meiosis II.

Nondisjunction occurs when homologous chromosomes or sister chromatids fail to separate during meiosis, resulting in an abnormal chromosome number. Nondisjunction may occur during meiosis I or meiosis II.

  

The incidence of having a fetus with trisomy 21 increases dramatically with maternal age.

The incidence of having a fetus with trisomy 21 increases dramatically with maternal age.

  

Pericentric inversions include the centromere, and paracentric inversions do not. A pericentric inversion can change the relative lengths of the chromosome arms; a paracentric inversion cannot.

Pericentric inversions include the centromere, and paracentric inversions do not. A pericentric inversion can change the relative lengths of the chromosome arms; a paracentric inversion cannot.

  

When one chromosome undergoes an inversion but the other does not, one chromosome must form an inverted loop to retain point-for-point interaction during synapsis.

When one chromosome undergoes an inversion but the other does not, one chromosome must form an inverted loop to retain point-for-point interaction during synapsis.

  

A reciprocal translocation occurs when a segment of DNA is transferred from one chromosome to another, nonhomologous chromosome.

A reciprocal translocation occurs when a segment of DNA is transferred from one chromosome to another, nonhomologous chromosome.

  

Proofreading by DNA polymerase corrects errors during replication

Proofreading by DNA polymerase corrects errors during replication

  

In mismatch repair, the incorrectly added base is detected after replication.

In mismatch repair, the incorrectly added base is detected after replication.

  

Nucleotide excision repairs thymine dimers. When exposed to UV, thymines lying adjacent to each other can form thymine dimers. In normal cells, they are excised and replaced.

Nucleotide excision repairs thymine dimers. When exposed to UV, thymines lying adjacent to each other can form thymine dimers. In normal cells, they are excised and replaced.

  

Mutations can lead to changes in the protein sequence encoded by the DNA

Mutations can lead to changes in the protein sequence encoded by the DNA

  

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