What information can a karyotype reveal?

• A. The visual arrangement of chromosomes showing number and structural abnormalities such as trisomies
• B. The expression levels of genes in a tissue
• C. The three-dimensional structure of a protein
• D. The sequence of nucleotides in a gene

Answer: (C)

The main idea here is what a karyotype can show about chromosomes. A karyotype is the visual arrangement of all the chromosomes, used to check how many there are and whether there are large structural changes. It can reveal numerical abnormalities like trisomies (an extra copy of a chromosome) and big rearrangements such as deletions, duplications, or translocations that affect chromosome structure. It does not provide information about how much or where genes are being expressed in a tissue (that needs RNA data), it doesn’t show the three‑dimensional shape of a protein, and it doesn’t reveal the exact nucleotide sequence of a gene (that requires DNA sequencing). So the information a karyotype best provides is the number and large-scale structural features of chromosomes.