in Fundamentals of Genetics by

1 Answer

0 votes
by

Crossing-over in homologous chromosomes occurs at the leptotene stage of prophase I in the first meiotic division. It is a physical exchange of chromosomal segments at corresponding positions which give rise to genetic recombination. It may produce new gene combination. Genetic material is neither loss nor gain during crossing-over.

Biology Questions and Answers for Grade 10, Grade 11 and Grade 12 students, Junior and Senior High Schools, Junior Colleges, Undergraduate biology programs and Medical Entrance exams.
...