Samenvatting
Summary Genetics Chapter 19
Summary genetics chapter 19 that helped me pass the course with a 8.5!
[Meer zien]Voorbeeld 2 van de 10 pagina's
Voorbeeld 2 van de 10 pagina's
In winkelwagengesponsord bericht van onze partner
Gekoppeld boek
Titel boek:
Auteur(s):
- Uitgave:
- ISBN:
- Druk:
Voorbeeld van de inhoud
Chapter 19Mutation Heritable change in the genetic material and also used for the genetic changes in somatic cells, think of
mutations in cancer cells. Provide allelic variation:
On the positive side, mutations are the foundation for evolutionary change needed for a
species to adapt to changes in the environment
On the negative side, new mutations are much more likely to be harmful than beneficial to
the individual and often are the cause of diseases
Since mutations can be quite harmful, organisms have developed ways to repair damaged DNA.
Three main 1. Chromosome mutations: Changes in chromosome structure (deletions, duplications, inversions,
types translocations,)
2. Genome mutations: Changes in chromosome number (aneuploidy, euploidy)
3. “small’ mutations: 1 up to a few bases: Relatively small changes in a DNA sequence (base order)
that occur within a particular gene or its promoter.
Mutations Indels: insertions, deletions
change DNA Mutations may also involve the addition or deletion of short
sequence sequences of DNA.
Point mutations = change in a single base pair -> involves base substitution.
- A transition is a change of a pyrimidine (C, T) to another pyrimidine or a purine (A, G) to another
purine
- A transversion is a change of a pyrimidine to a purine or vice versa
Transitions are more common than transversions
Gene silent mutation:
mutations can genetic code is
alter the degenerate (third
coding base).
sequence
within a gene Neutral mutation:
when missense
mutation has no
detectable effect
on protein
function (or/and
silent mutations).
Missense
mutation: sickle
cell disease.
Glutamic acid -> valine. Single substitution has profound effect on phenotype of cell and even causes
serious disease.
Mutation in Can still effect gene expression:
noncoding 1. A mutation, may alter the sequence within a
sequences promoter
- Up promoter mutations make the promoter
more like the consensus sequence. They may
increase the rate of transcription
- Down promoter mutations make the promoter
less like the consensus sequence. They may
decrease the rate of transcription
Mutation can alter splice junctions in eukaryotes.
Example mutation in operator: lacOc -> prevented
binding of lac repressor, causes lac operon to always be expressed even if lactose is not present. Energy
, waste.
Gene In a natural population, the wild-type is the relatively prevalent genotype.
mutations - A forward mutation changes the wild-type genotype into some new variation
and their - A reverse mutation changes a mutant allele back to the wild-type: It is also termed a reversion
effect on (rare)
genotype and
phenotype Mutation can also be described based on their effects on the wild-type phenotype: when a mutation alters
an organism’s phenotypic characteristics, it is said to be a variant or mutant. Variants are often
characterized by their differential ability to ‘survive’, but it is not only survival.
- Deleterious mutations decrease the chances of survival -> The most extreme are lethal mutations
- Beneficial mutations enhance the survival or reproductive success of an organism
>> Some mutations are called conditional mutants
They affect the phenotype only under a defined set of conditions -> An example is a temperature-sensitive
mutation
Mutations in Germ-line mutations: mutations in
germ-line cells: cells that give rise to
gametes such as eggs and sperm: occur
directly in a sperm or egg cell, or in one
of their precursor cells.
Somatic mutations: mutations in
somatic cells (all other cells): occur
directly in a body cell, or in one of its
precursor cells.
Genetic mosaic.
Random Mutations can occur spontaneously or be induced.
nature of Spontaneous mutations: Result from abnormalities in cellular/biological processes. Errors in DNA
mutations replication during ‘cell division’ and DNA repair.
Induced mutations: Caused by environmental agents: Agents that are known to alter DNA structure
Rates of are termed mutagens: These can be chemical or physical agents
spontaneous
mutation per
cell
generation
typically
range from
10-5 to 10-9.
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper mabel46. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €3,39. Je zit daarna nergens aan vast.
Is Stuvia te vertrouwen?
4,6 sterren op Google & Trustpilot (+1000 reviews)
Afgelopen 30 dagen zijn er 76449 samenvattingen verkocht
Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen