Unequal crossing over during prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of haemoglobin, so-called haemoglobin Lepore, exists in the human population. Haemoglobin Lepore has a deleted series of amino acids. If this mutated form was caused by unequal crossing over, what would be an expected consequence?
A) There should also be persons whose haemoglobin contains two copies of the series of amino acids that is deleted in haemoglobin Lepore.
B) Each of the genes in the haemoglobin gene family must show the same deletion.
C) The deleted gene must have undergone exon shuffling.
D) The deleted region must be located in a different area of the individual's genome.

Question

Quizplus · Accepted Answer

Unequal crossing over can result in one chromosome having a deletion and the other having a duplication. In the case of haemoglobin Lepore, the mutated form has a deleted series of amino acids. If this was caused by unequal crossing over, it would be expected that some individuals would have two copies of the deleted series of amino acids, leading to a potential duplication of the gene. Therefore, option A is the best choice.

Unequal Crossing Over During Prophase I Can Result in One