What is the Difference Between a Linkage Map and a Physical

Question

What is the difference between a linkage map and a physical map?
A) For a linkage map, markers are spaced by recombination frequency, whereas for a physical map they are spaced by numbers of base pairs (bp).
B) For a physical map, the ATCG order and sequence must be achieved; however, it does not for the linkage map.
C) For a linkage map, it is shown how each gene is linked to every other gene.
D) For a physical map, the distances must be calculable in units such as nanometers.
E) There is no difference between the two except in the type of pictorial representation.

Accepted Answer

A linkage map is based on the frequency of recombination events between genetic markers, whereas a physical map is based on the physical distance between markers in base pairs. This means that the markers on a linkage map will be spaced by recombination frequency, while on a physical map they will be spaced by the number of base pairs between them.

Answer: B
 A physical map is based on the actual sequence of DNA and requires the identification of specific markers or sequences along the DNA molecule. A linkage map, on the other hand, does not require knowledge of the actual DNA sequence, only the frequency of recombination events between markers.

Answer: D
 Distances on a physical map are typically measured in units such as nanometers or base pairs, while distances on a linkage map are typically measured in map units or centimorgans. The physical map is a representation of the actual physical distance between markers, whereas the linkage map represents the genetic distance between markers as determined by recombination frequency.