Test 3- Mutations and Mendelian Genetics Flashcards Preview

Genetics > Test 3- Mutations and Mendelian Genetics > Flashcards

Flashcards in Test 3- Mutations and Mendelian Genetics Deck (28):
0

point mutations

bp substitution
missense mutation
nonsense mutation
neutral mutation
frameshift
forward
reverse
suppressor

2

bp substitutions

transition
transverion

3

transition

AT-GC

4

transversion

AT-TA

5

missense mutation

different aa inserted

6

nonsense mutation

premature stop codon

7

neutral mutation

no change in protein function

8

silent mutation

no change in aa

9

frameshift mutation

changes reading frame w/ addition or deletion

10

forward mutation

wt to mutant

11

reverse mutation

mutant to wt
true: back to wt aa
partial: change that restores partial function

12

suppressor mutation

mutation at another site that diminish or abolish affect of original mutation
intragenic: same gene
intergenic: different gene
-tRNA nonsense suppressor

13

spontaneous mutations

replication errors
-tautomeric shift
-insertion/deltion
-chemical changes (depurination/deamination)

14

tautomeric shifts

AC and TG base pairing

15

insertion/deletion

looping occurs in regions with repeated bp sequence

16

depurination

A or G bond to sugar breaks losing base

17

deamination

removes amino group from base
C to U, 5mC to T

18

induced mutation

ionizing
-xrays
UV light
chemical mutagens
-base analogs
-base modifiers
-intercalating agent

19

xrays

break sugar phosphate backbone

20

UV

forms thymine dimers

21

Base analogs

5 bromo-uracil (like T)
bp in enol state with G (TA to CG)

22

base modifiers

nitrous acid
-deaminates GCA (G no effect)
-causes transition mutations
-can revert
hydroxylamine
-hydoxylates C to pair with A
-cant revert
alkylating agents
-MMS/EMS
-GC to AT

23

intercalating agents

proflavin, acridine, ethidium bromide
cause bp insertions/deletions by inserting into helix

24

ames test

tests for mutagens
his auxotrophs plated with liver enzymes and potential mutagen to look for revertants as seen by inc. growth

25

dna repair

dna pol 3'-5' exonuclease activity
light repair of T^T- photlyase dimer activated by light, splits dimer
demethylation of G by methyltransferase
base excision (cut out and DNA pol and ligase fill in)
nucleotide excision (uvrA and B scan for damage; A released/ C binds; cut; D unwinds; DNA pol I and ligase fill)
methyl directed mismatch repair (MutS binds mismatch; MutL and H bind with unmethylated GATC and S; MutH nicks strand, exonuclease removes mismatch; DNA pol III and ligase fill)
SOS response (RecA filament kicks off LexA repressor which synthesizes SOS (pol IV or V), pol III synthesizes to mutation, pol IV or V synthesize at mutation, pol III finishes)

26

law of segregation

two members of gene pair segregate from each other during meiosis

27

law of independent assortment

genes on different chromosomes behave independently during meiosis

28

chromosomal theory of inheritance

sutton and boveri- chromosomes transfer like mendels factiors
stevens and wilson- x chromosome and sex link
morgan- white eyed male fly doesnt fit 3:1
bridges- nondisjunction