Chromosome representation in cytogenetics A diagrammatic depiction of the haploid set of chromosomes of an organism, ordered by decreasing size (and banding), is called what?

Introduction / Context:
Cytogeneticists use standardized visual representations of chromosomes to describe number, size, and banding. Two closely related terms—karyogram and idiogram—are often confused. Clarifying the distinction helps students read primary literature and clinical reports correctly.

Given Data / Assumptions:

• The question specifies a diagram of a haploid set, ordered by decreasing size.
• Focus is on schematic, not a photographic plate.
• Banding and centromere positions are shown abstractly in many cases.

Concept / Approach:
An idiogram (also called ideogram) is a schematic drawing of chromosomes aligned and ordered, typically by size and centromere position, often with banding patterns indicated. A karyogram is the actual arranged image (photograph/micrograph) of metaphase chromosomes. Zymograms relate to enzymes/proteins separated by electrophoresis, not chromosomes.

Step-by-Step Solution:

Verification / Alternative check:
Many cytogenetics textbooks define idiogram/ideogram as the diagrammatic representation, often paired with a karyotype description summarizing the chromosome set.

Why Other Options Are Wrong:

• Zymogram: enzyme pattern visualization; unrelated to chromosomes.
• Chromogram: non-standard term in this context.
• Karyogram: refers to a photographic arrangement rather than a schematic drawing.
• Proteogram: protein profile, not cytogenetic.

Common Pitfalls:
Interchanging idiogram and karyogram; always ask whether the source is a schematic or an image.

Final Answer:
Idiogram