Chapter 5 book Flashcards
Syntenic genes
genes on same chromosome
Gene linkage
2 syntenic gens don’t assort independently
Homologous recombinants
process that occurs when crossing over in prophase I
recombinant chromosomes
nonparental chromosomes from reshuffling of alleles
Parental chromosomes
Homologous chromosomes that don’t crossover retain the same alleles as parents
What happens if the syntenic genes are closer together
They will recombine less than farther genes
What are linked genes also
syntenic genes
If genes are linked what is the likely outcome of the gametes
more gametes with parental chromosomes
genetic linked mapping
plots points of genes on chromosomes
If there is gene linkage explain the percentage of offspring
Parentals will by 50% or greater than recombinants
Recombination frequency formula
of recombinants/ total # of offspring
What did William Bateson and Reginald Punnett study
flower color and shape of pollen in sweet peas
PPLL purple and long crossed with ppll red and short and produced PpLl purple and long. F1 was then self crossed and produced P_L_ 4831, P_ll 390, ppL_ 393, and ppll 1338. What does this show
The 2 parental alleles stayed together frequently
Who created the first gene linkage map?
Morgan
2 point test cross analysis
F1 crossed with recessive where 2 genes are test
What is the distance of vg and pr
when vg+pr+/vgpr has a 2 point test cross analysis to produce
vg+pr+/vgpr= 1339
vgpr/vgpr=1195
vg+pr/vgpr=154
vgpr+/vgpr=151
305/2839=.1
10 centimorgan
centiMorgan
units of physical distance by recombination frequency
double crossover
2 genes switch simultaneously and least frequent
interference
reduction of number of double crossovers relative to number of expected caused by
interference formula
1- coco
coefficient of coincidence formula
Observed double/ expected double
how do you find the expected double
total(a-b distance)(b-c distance
explain how you find gamete frequencies from genetic maps
distance is recombo so divide by 1/2 to get each half. parentals subtract 100- distance then divide by 1/2
mapping function
correlates map distance and recombo frequency
