Paper 2 · Inheritance and Variation
During metaphase I of meiosis the bivalents line up at random on the equator. This is important because it
Aallows each chromosome to be copied a second time before the cell divides again
Bmakes certain that every one of the gametes that is produced receives one complete maternal set of chromosomes
Cmeans maternal and paternal chromosomes are assorted independently, giving many different gamete combinations
Dkeeps the maternal and paternal chromosomes of each pair together in the same gamete
Explanation: Which member of a pair faces which pole is decided independently for every bivalent. With 23 pairs in a human that alone gives over eight million possible chromosome combinations in the gametes, before crossing over adds any more.
Derived from ZIMSEC Biology Paper 2, Nov 2004, Q11