What is the primary difference between a gene mutation and a chromosome mutation?

• A. Gene mutations affect the sequence of nucleotides within a single gene, while chromosome mutations involve changes in the structure or number of entire chromosomes.
• B. Gene mutations are always beneficial, while chromosome mutations are always harmful.
• C. Gene mutations result in changes to the entire chromosome, whereas chromosome mutations only affect individual genes.
• D. Gene mutations occur during meiosis, whereas chromosome mutations occur during mitosis.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a gene mutation: A gene mutation is a change in the nucleotide sequence of a specific gene. This can involve substitutions, insertions, or deletions of nucleotides within the gene.
2. Understand the definition of a chromosome mutation: A chromosome mutation involves changes in the structure or number of entire chromosomes. This can include deletions, duplications, inversions, or translocations of chromosome segments, or changes in chromosome number such as aneuploidy.
3. Compare the scope of impact: Gene mutations affect only a single gene, altering its nucleotide sequence, while chromosome mutations can affect multiple genes by altering the structure or number of chromosomes.
4. Clarify the misconception about the effects: Gene mutations are not always beneficial; they can be neutral, beneficial, or harmful. Similarly, chromosome mutations are not always harmful; their effects depend on the specific changes and context.
5. Differentiate the processes: Gene mutations can occur during DNA replication, which can happen in both mitosis and meiosis. Chromosome mutations often occur during cell division processes like meiosis, where errors in chromosome segregation can lead to changes in chromosome number or structure.