Genetic linkage

Genetic linkage occurs when particular allelesinherited together. Typically, an organism can pass onallele without regardwhich allele was passed on fordifferent gene. Thisbecause chromosomessorted randomly during meiosis. However, alleles whichonsame chromosome more likelybe inherited together andsaidbe linked.

Because theresome crossing overDNA whenchromosomes segregate, alleles onsame chromosome can be separatedgodifferent cells. Theremuch more chancethis happening ifallelesfar apart onchromosome, as itmore likely thatcross-over will occur between them.

The physical distance between two genes can be calculated usingoffspringan organism showing two linked genetic traits,findingpercentagechildren wheretwo traits don't run together. The higherpercentageoffspring that don't show both traits,further apart onchromosomeare. A study oflinkages between many genes enablescreation oflinkage map.