AP BIOLOGY

Detailed explanation-1: -The chiasmata is the point where two homologus non-sister chromatids exchange genetic material during crossing over. It becomes visible at the diplotene stage of prophase I. It links homologous chromosomes together till anaphase I and gets separated. So the correct answer is ‘Anaphase I’.

Detailed explanation-2: -The chiasmata become visible during the diplotene stage of prophase I of meiosis. but the actual “crossing-over” of genetic material is thought to occur during the pachytene stage.

Detailed explanation-3: -The chiasmata become visible during the diplotene stage of prophase I of meiosis, but the actual “crossing-overs” of genetic material are thought to occur during the previous pachytene stage.

Detailed explanation-4: -Chiasmata are points where two homologous non-sister chromatids exchange genetic material during crossing over in meiosis. Chromosomes intertwine and break at the exact same positions in non-sister chromatids. The two chromosomes are now attached at the same corresponding position on the non-sister chromatid.

Detailed explanation-5: -The correct answer is (c) synapsis and crossing over. 1. During prophase I of meiosis, synapsis and crossing over take place.