Ch 15 Non Medelian Genetics Flashcards
chromosome theory of inheritance
Mendelian genes have specific loci (sites) along chromosomes, and it is the chromosomes that undergo segregation and independent assortment.
wild type
the phenotype for a character most commonly observed in natural populations
sex linked gene
genes on either sex chromosome, many unrelated to sex
X - 1,100
Y - 78
Hemophilia
X linked recessive disorder
Barr Body
Condensed inactive X in each cell of a female
linked genes
genes located near each other on the same chromosome; tend to be inherited together in genetic crosses
genetic recombination
the production of offspring with combinations of traits that differ from those found in either P generation parent
parental types
when phenotypes of offspring match the P generation
recombinant types/recombinants
phenotypes are new combinations
crossing over
the recombination of linked genes
genetic map
an ordered list of the genetic loci along a particular chromosome
linkage map
a genetic map based on recombination frequency
map unit
one map unit is 1% recombination frequency
nondisjunction
one gamete receives two of the same type of chromosome
aneuploidy
either of the aberant (abnormal) gametes unites with a normal one at fertilization, the zygote will also have an abnormal number of a particular chromosome
monosomic - the cell has 2n-1 chromosomes
trisomic - has 2n+1 chromosomes
deletion
error in meiosis where a chromosomal fragment is lost
duplication
error in meiosis where a broken fragment becomes reattached as an extra segment
inversion
error in meiosis where a chromosomal fragment reattaches to the original chromosome
translocation
error in meiosis where a fragment joines a nonhomologous chromosome
genomic imprinting
expresson of an allele in offspring depends on whether the allele is inherited from the male or female parent
