Chromosome Mutations

2 Pages
64 Views
Unlock Document

Department
Biological Sciences
Course
BIOC31H3
Professor
Malcolm Mac Kinnon
Semester
Fall

Description
5.3 Chromosome Mutations  Inversions o Often result from a multistep process that starts when radiation causes two double- strand breaks in a chromosome.  After a breakage, the chromosome segment can detach, flip, and reanneal in its original location (Fig. 5.9).  In addition to involving much larger stretches of DNA that point mutation and gene duplications, inversions produce very different consequences  Affect a phenomenon known as genetic linkage o Linkage is the tendency for alleles of different genes to assort together at meiosis o Read example of the fly on page 157  Inversions change gene order and lessen the frequency of crossing over between homologous segments of chromosomes. As a result the alleles inside inversions tend to be inherited.  Inversion are an important class of mutations because they affect selection on groups of alleles  Genome Duplication o Occurs at the largest scale possible; entire sets of chromosomes  For example: if homologous chromosomes fail to segregate during meiosis I or if sister chormatids do not separate properly during meiosis II, the resulting cells may have double the chromosomes of the parent cell  Mutations like these can lead to the formation of a diploid gamete in species where gametes are normally haploid o Organisms that have more than two chromosome sets are said to be polyploidy.  This is common in plants, but rare
More Less

Related notes for BIOC31H3

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit