question_answer

The point at which crossing over occurs is called as :

A)  chiasmata                          

B)  centromere

C)   chromosome                  

D)  gene loci

Correct Answer: A

Solution :

                 Chiasmata is the point of attachment between non-sister chromatids of two homologous chromosomes. Crossing over i.e., exchange of segments between nonsister chromatids of a bivalents occurs at chiasmata during pachytene stage of prophase-I. Two chromatids of a chromosome is jointed at a point known as centromere. Chromosome is a genetic material. Each chromosome consist of two coiled filaments known as chromatids or chromonemata.