What does the term "crossing over" mean and how does cross-over occur?
Cross-over occurs in meiosis after the chromosomes are aligned. The chromosomes connect at the centromere and prepare to split. Before the two chromosomes split, alleles on the chromosomes switch loci. This is crossing over, when two alleles switch loci between chromosomes.
These chromosomes are in the meiosis cycle. Figure A shows the chromosomes lined up with each chromosome containing different alleles (black and white). Figure B shows the chromosomes after cross-over has occured. Now each chromosome has one copy of each allele.
Crossing over occurs in a) mitosis or b) meiosis?
True or False: Before the chromosomes split, two of the alleles switch gene loci.
Created By: Chelsea K. Lattas