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Flashcards in G10-11 Deck (22):
1

What is forward genetics

phenotype -> gene
asks what genes are involved in a bioligical process

2

what is reverse genetics

gene -> phenotype
ask what biological processes a gene is involved in

3

what does the chemical mutagen EMS do?

adds ethyl group to O-6 position of Guanine (alkylation)
Et-G now pairs with T. G:C to A:T transition

4

what are the possible outcomes of EMS mutagenesis

mispairing not detected: DNA replication fixes the mutation GC to AT transition
repair by de-ethylation O-6 alkylguanine DNA transferase
Repair by base excision: could lead to transversion, frameshift, DSB etc

5

what are forward genetic screenings easier in?

hermaphrodites

6

What are the 6 mutation types

null
hypomorph
haploinsufficient
neaomorphic
hypermorphic
antimorphic

7

what is a hypomorphic mutation

partial loss of gene function, reduced level of activity, wild type expressed at a reduced level

8

what is a haploinsufficient mutation

diploid organism has only single functional copy not enough gene product produced to bring about wildtype

9

what is a neaomorphic mutation

change in gene leads to atypically new function of gene

10

what is a hypermorphic mutation

gain of cuntion, increase in an otherwise normal gene function

11

what is an antimorphic mutation

antagonizes normal gene function.

12

how can you work out if mutation is true null? why might it not be

could be hypomutation etc
genetic analysis required

13

what are the steps after mutagenesis

outcross to see if breeds true
determine mutation type
complementation tests
mapping

14

what bias is shown if mutation is linked to a marker?

bias towards mutant parent band

15

what is a modifer screen?

when a an organism with a pre-existing phenotype is selected, thus any mutations caused by mutagen (EMU) can be assessed for their enhancive to suppressive activity.

16

what kind of insect is drosophilia melanogaster?

a homolemetabolous insect, - complete metamorphism egg-> larva to pupa to fly

17

why is drosophilia melanogaster a good model organism

50% of fly genes have vertebrate homologs, small and easy to grow in the lab with a short life cycle and high amount of offspring.

18

give two examples of homeotic mutants

bithorax where T3 segment is replaced bya second T2
antennapedia - antennae into legs.

19

what is intragenic complementation

when mutations in the same gene complement - eg. multifunctional proteins.

20

what is extragenic non complementation

non allelic non complementation mutations in two different genes fail to complement - eg. subunit of same protein complex.

21

what did mice mutaants targeted for knockout of HoxC8 gene reveal?

rib duplication and clenched finger phenotype

22

what do homeotic genes code for?

a class of transcirption factors called homeodomain proteins.