Exam Two Terms Flashcards
(20 cards)
locus (loci)
specific position where gene or genetic marker is located
independent assortment
alleles of two (or more) different genes get sorted into gametes independently of one another
linkage
genes on the same chromosome segregate together
complete linkage
no exchange or crossing over
partial linkage
crossing over between tow genes (on non-sister chromatids) creates recombinant chromosomes
no linkage
independent assortment of genes on different chromosomes
chiasma (chiasmata)
where physical crossing over occurs between non sister chromatids
sister chromatid
identical copies formed by DNA replication of chromosomes
parental class
original arrangement of alleles on two chromosomes
recombinant class
- new class not present in parents
- observed less frequently then parental class
coupling (cis)
two dominant alleles on one homolog and two recessive alleles on the other
repulsion (trans)
one dominant and one recessive allele on each homolog
interlocus distance
The distance between any two loci on a single chromosome
recombination frequency
percentage of offspring resulting from recombinant gametes
map unit
1% recombination between two genes on a chromosome
trihybrid
individual or strain that is heterozygous for three pairs of genes
single crossover (SOC)
used to determine the DISTANCE between tow genes on a chromosome
double crossover (DCO)
used to determine the ORDER of genes on the chromosome (middle gene is switched)
Interference
the fraction of the expected double crossovers that hare inhibited from occurring
Coefficient of coincidence
fraction of expected double crossovers that actually occurs
