Question

The karyotype indicates a problem with chromosome 18. What is the problem and what is the BEST explanation for why it occurred?

A) extra chromosome; insertion
B) foreign chromosome; deletion
C) extra chromosome; nondisjunction
D) mutated chromosome; crossing over

Answer 1

C) extra chromosome; nondisjunction

Answer 2

The correct answer would be C) extra chromosome; nondisjunction.

Karyotype is the diagrammatic representation of the number and appearance of the chromosomes of an organism.

The normal karyotype of a human being consists of 23 pairs of chromosomes.

In the given karyotype shows trisomy of chromosome 18 that is, it contains an extra copy of the chromosome.

Extra copy of a chromosome is inherited as a result of nondisjunction (failure of separation of sister chromatids or homologous chromosomes) during gamete formation.