Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
In which step of prophase I does crossing-over occur?
A
Leptonema
B
Zygonema
C
Pachynema
D
Diplonema
E
Diakinesis
Verified step by step guidance
1
Understand the stages of prophase I in meiosis, which include Leptonema, Zygonema, Pachynema, Diplonema, and Diakinesis.
Recognize that crossing-over is a critical event in meiosis where homologous chromosomes exchange genetic material to increase genetic diversity.
Identify that crossing-over occurs during the Pachynema stage of prophase I.
During Pachynema, homologous chromosomes are fully synapsed, forming structures called tetrads, which facilitate the exchange of genetic material.
Note that the process of crossing-over is facilitated by the formation of chiasmata, which are visible during the later stages of prophase I, such as Diplonema.