BIOLOGY 1A03 Chapter Notes - Chapter 20: Noncoding Dna, Meiosis, Prophase

• School: McMaster University
• Department: Biology
• Course: BIOLOGY 1A03
• Professor: Rosa Da Silva

Document Summary

A hit means that the orf shares a significant amount of sequence with a known gene from another species. Sequencing eukaryotic genomes presents 2 challenges: size, noncoding sequences that are repeated many times. When noncoding and repeated sequences were discovered they were initially considered. Strs: small sequences repeated one after another contiguously along part of a chromosome. Hypervariable: vary among individuals much more than any other type of sequence does. Repeated sequences are prone to unequal crossover because their homologs are so similar that they are likely to misalign. This variation in repeat number among individuals is the basis of most dna fingerprinting. The major source of new genes is the duplication of existing genes. Within a species genes that are extremely similar to each other in structure and function are considered to be part of the same gene family. The degree of sequence similarity among members of a gene family varies.