Question

homework - genetic disorders

what is the best description of the individual represented by this karyotype?

female who has experienced a mutation in which a gene segment was translocated to a new chromosome

female who has experienced a deletion mutation of several base pairs from a chromosome.

male who has experienced a mutation in which extra base pairs were added to a chromosome.

male who has experienced a nondisjunction mutation of one or more chromosomes.

Explanation:

• Determine gender: In a karyotype, the 23rd pair (sex chromosomes) determines gender. Males have an XY pair, and females have an XX pair. Here, the 23rd pair has two different - sized chromosomes (XY), so it's a male.
• Analyze mutation type:
• Translocation: A segment of one chromosome breaks off and attaches to another non - homologous chromosome. There is no indication of such a rearrangement in the karyotype.
• Deletion: A loss of a segment of a chromosome. No such missing segments are visible.
• Addition of base pairs: This is a gene - level mutation (microscopic) and not visible in a karyotype (which shows chromosome - level changes).
• Nondisjunction: Occurs when chromosomes fail to separate properly during cell division. In this karyotype, there is an extra chromosome (for example, if we assume a normal diploid set of 46 chromosomes, and here there seems to be an extra chromosome in one of the pairs, which is a result of nondisjunction during gamete formation).

Answer:

Male who has experienced a nondisjunction mutation of one or more chromosomes.