exam 3 question pool Flashcards
(85 cards)
what are viruses composed of?
most plant and animal viruses have __ genes and viruses that infect bacteria have ___ genes
solely DNA or RNA in protein coat
> 10 genes
10-100
HIV–> 9
difference between lytic and lysogenic lifestyle?
cells carrying a prophage are resistant to ?
lytic– replication then kill host
lysogenic— integrated into host genome (prophage), replicated, sits dormant can become active
infection by same phage genotype
what is generalized transduction?
virus shatters host cells genomes during lytic life cycle
accidentally packed into host DNA instead of viral DNA
movement of 2 genes by same virus
what is specialized transduction?
DNA from same region of genome is always taken from the host & put into the next host cell
-lambda phage is example
what is transformation vs transduction?
take up of DNA from environment
via phage
how would we culture bacteria in a lab?
what shows on plate & in liquid?
mix bacteria + phage, grow, wait for phage to lyse bacteria
plate: bacteria forms lawn, lysed cells form plaques
liquid: bacteria is cloudy, lysis is clear
what is high and low MOI?
low MOI <1 phage per cell–> good to assess geno + phenotype
high MOI > 2 phage per cell–> used for complementation, recombination
what is cotransduction?
depends on distance between 2 genes
higher frequency for those that are closer together
what happens in complementation if mutant is in same vs different genes?
same— F1’s of 2 mutants will be mutant
different genes– 2 mutants will give a normal F1 (complement)
what is the difference between complementation & recombination test?
comp: infect at high MO1
recombination:
infect at high MOI for recombination
infect at low MO1–> get geno & phenotype
on a bell shaped curve, when it becomes more normal…..
what is phenotypic variance?
less observances deviate from the mean
extend of how individuals deviate from the mean
what are components of Vp?
Vp= Vg + Ve
phenotypic varience= variance in genes + variance in environment
what happens when you have 2 true breeding parents?
what about when F1’s cross?
Vg=0, only environmental factors work on it–> will have slim peak
3:1 ratio, both Vg and Ve affect–> wide peak, less normal
how to get Vg when dealing with F1 and F2?
how to get heritability?
Vg= VpF2 - VpF1
VpF2–> Vg +Ve
VpF1–> Ve
Vg/Vp
if H2 is 0–> parent height has no influence on Childs height
what happens to the mean with a highly vs low heritable trait?
high–> mean changes ALOT per generation
low–> mean does not change
how do you identify QTL?
then how do you map it?
shows the least of amount of recombination– so less heterozygotes & less frequency of recombination
AND has greatest amount of variation between means of different extremes
recombinant/ total X 100
what are HWE assumptions?
infinity large population
no over lapping generations–> complete turnover of genotype at each generations
random mating! (sexual selection is violation)
NO mutation, NO migration, NO selection
for alleles in low frequency, what form are they often found in?
heterozygotes
how does HWE work for X linked traits??
males :
P + q
females:
P2
2pq
q2
how does migration affect HWE?
how to restore?
this will alter allele frequencies OF BOTH populations
— A source of gene flow
after random mating, will restore HWE back
what does inbreeding and assortive mating do to HWE?
violates random mating
assortive mating is when mate choice is not random
- impact depends on details of selective mating
- ALTERS allele/ genotype frequencies
inbreeding causes likelihood of more homozygotes
- decrease Aa
-increase AA or aa
- no overall change in allele frequency
what does mutation cause?
mutations can be?
halotypes–> collection of mutations on single chromosome
advantageous, deleterious, no effect
what is directional selection?
pushes population toward HOMOzygousity
-decreases variation within population, increases differences AMONGST populations
what is balancing selection?
what is over and under dominance?
for genes that show complete dominance
– over: heter zygote more fit
- under: homozygot morę fit