Question

Differentiate between single crossing over and double crossing over.

Answer 1

Aspect	Single Crossing Over	Double Crossing Over
Number of Chiasmata	In single crossing over, there is only one chiasma where chromatids of homologous chromosomes contact.	In double crossing over, the crossing over occurs at two points in the same chromosome pair, forming two chiasmata.
Points of Chromosome Breakage	The chromosomes break only at one point along their entire length.	The chromatids break and rejoin at two different points along the chromosome length.
Chromosomal Shape Formed	Bivalents having a single chiasma appear as open crosses.	Two chiasmata produce a ring shape in the chromosome pair.