BIOL 202 Lecture Notes - Lecture 28: Genetic Testing, Rous Sarcoma Virus, Brca2
Document Summary
Inversion inversion can cause twisting of dna in order to find homologous sequences. Formation of loop (different from deletion loop) results in a decrease in the frequency of recombinant offspring since the deletion could lead to lethality. When crossover occurs, it results in uneven exchange of genetic material (due loops include the centromere to inversion) Depending on where centromere is located, creation of dicentric chromosome or improper crossover will occur (duplication of a segment in a single chromosome: dicentric chromosomes are formed via paracentric inversion of a heterozygote. During meiosis, the chromosomes will align to their homologous sequences these homologous sequences are organized differently due to translocation. Two types of segregation translocation between 2 different heterologous chromosomes: adjacent-1 (often inviable) T1+n2 (up) = duplication of purple, deletion of orange translocated segment. N1+t2 (down) = duplication of orange, deletion of purple: alternate (complete and viable) Robertsonian translocation can lead to down"s syndrome:
