Genetic Linkage & mapping in eukaryotes 3 Flashcards
Genetic Map
A diagram that describes the order of genes along a chromosome
Synteny
Two or more genes are located on the same chromosome
Genetic linkage (linkage)
Genes that are close together on the same chromosome tend to be transmitted together
Crossing over
Chromsomes exchanging alleles with one another (usually occurs in prophase of meiosis 1)
Crossing over may produce ___________
Recombinant genotypes
Recombinant offspring
Have different combination of alleles then the orginal cell (parent)
Genetic Recombination
When offsprings have combination of alleles (or traits) that are different from the parents
_______________ are produced by the exchange of DNA between two homologous chromosomes during meiosis & results in combination of traits different from parents
Recombinant offspring
____________ carries chromosomes that are the product of crossing over
Recombinant offspring
The likelihood of crossing over to occur between two genes depends on what?
The distance between them
If two genes are __________ then crossing over is likely to occur
Far apart
If two genes are _________ then crossing over isn’t likely to occur
Close together
A ________ can be used to distingiush between the linkage & independent assortment
Chi Square Test
Genetic Mapping
Used to determine the linear order & distance among genes that are linked to each other on the same chromosome
Locus
Where a gene is located
The frequency of ___________ between two genes is used to determine the mapping distance between two chromosomes
Recombination
______________ can give hints to the distance of the genes like if there a high percentage of recombinant offspring then the genes must be far apart & if there is a low percentage they must be closer to each other
Recombinant offspring
Genetic mapping is only relevant with ___________ parents
Heterozygote
Map distance calaculation
of recombinant offspring / # of offspring x 100
Mitotic Recombination
When mitotic crossing over produce a pair of recombinant chromosomes that have a new combination of alleles
________ provide evidence that mitotic recombination had occur
Twin spots
