Which term describes a picture of an organism's genome used for chromosomal analysis?

Which term describes a picture of an organism's genome used for chromosomal analysis?

• A. Genome
• B. Karyotype
• C. Chromosome count
• D. Nucleoid image

Answer: (B)

In chromosomal analysis, the organized image of all chromosomes from a cell is called a karyotype. A karyotype shows the number and appearance of chromosomes, typically arranged in pairs by size and banding pattern, and is prepared from cells arrested in metaphase and stained to reveal characteristic bands. This visual snapshot allows scientists to detect abnormalities such as extra or missing chromosomes, translocations, or structural changes. The other terms don’t fit as well: a genome refers to the entire set of genetic material, not a single chromosomal image; chromosome count is just the total number of chromosomes and doesn’t capture their size or structure; and a nucleoid image describes bacterial DNA organization, not the eukaryotic chromosome arrangement used in standard chromosomal analysis.

In chromosomal analysis, the organized image of all chromosomes from a cell is called a karyotype. A karyotype shows the number and appearance of chromosomes, typically arranged in pairs by size and banding pattern, and is prepared from cells arrested in metaphase and stained to reveal characteristic bands. This visual snapshot allows scientists to detect abnormalities such as extra or missing chromosomes, translocations, or structural changes. The other terms don’t fit as well: a genome refers to the entire set of genetic material, not a single chromosomal image; chromosome count is just the total number of chromosomes and doesn’t capture their size or structure; and a nucleoid image describes bacterial DNA organization, not the eukaryotic chromosome arrangement used in standard chromosomal analysis.