What is the primary result of a chromosomal mutation?

The primary result of a chromosomal mutation is that the number of chromosomes increases or decreases. Chromosomal mutations often involve large segments of DNA that can lead to changes in chromosome structure or number, such as duplications, deletions, inversions, or translocations. These alterations can cause significant changes in the genetic material of an organism, potentially affecting its phenotype and contributing to genetic diversity.

Other choices focus on smaller scale mutations, such as point mutations, which involve changes to single nucleotides like substitutions, insertions, or deletions. While these point mutations play important roles in genetic variation, they do not encompass the broader changes associated with chromosomal mutations, which are characterized by alterations in the whole chromosome or the overall chromosome count.