Physical map

Definition

A physical map is a representation of the arrangement of genes and genetic markers on a chromosome. It indicates the actual distance between these elements in base pairs, kilobases, or megabases.

5 Must Know Facts For Your Next Test

1. Physical maps provide precise locations of genes and markers based on DNA sequence data.
2. They are essential for identifying gene positions and understanding genome structure.
3. Techniques such as restriction mapping, FISH (Fluorescence In Situ Hybridization), and sequencing are used to create physical maps.
4. Physical maps differ from genetic maps by measuring actual physical distances rather than recombination frequencies.
5. These maps play a critical role in sequencing projects, including the Human Genome Project.

Review Questions

• What is the primary difference between a physical map and a genetic map?
• Which techniques are commonly used to create physical maps?
• Why are physical maps important for genome sequencing projects?

Related terms

Genetic Map: A representation of gene order and relative distances based on recombination frequencies.

Restriction Mapping: A technique used to determine the locations of restriction enzyme sites within a piece of DNA.

Sequencing: The process of determining the exact order of nucleotides in a DNA molecule.