The Following Question Refers to the Essential Steps in Meiosis

Multiple Choice

The following question refers to the essential steps in meiosis described below.
1. Formation of four new nuclei, each with half the chromosomes present in the parental nucleus
2. Alignment of homologous chromosomes at the metaphase plate
3. Separation of sister chromatids
4. Separation of the homologs; no uncoupling of the centromere
5. Synapsis; chromosomes moving to the middle of the cell in pairs
-When homologous chromosomes cross over, what occurs?

A) Two chromatids get tangled, resulting in one re-sequencing its DNA.
B) Two sister chromatids exchange identical pieces of DNA.
C) Specific proteins break the two strands of nonsister chromatids and re-join them.
D) Each of the four DNA strands of a homologous pair is broken, and the pieces are mixed.
E) Maternal alleles are "corrected" to be like paternal alleles, and vice versa.