Final answer:
A karyotype is a type of micrograph that shows the chromosomes of a cell, arranged typically by size, which helps identify chromosomal abnormalities and is an essential tool in cytogenetics.
Step-by-step explanation:
A karyotype is a micrograph which displays the chromosomes of a cell, usually in descending order of size. This diagnostic tool is crucial for cytogenetic studies and can be very telling in genetics and biology. Through microscopy, chromosomes are visualized, and these images are often referred to as micrographs. In a karyotype, chromosomes are stained to reveal unique banding patterns that assist in their identification, and the arrangement reflects their size, banding pattern, and the position of the centromere.
Karyotypes are valuable in identifying chromosomal anomalies such as monosomy or trisomy, which are impairments in chromosome number that can lead to genetic disorders. The figure from a fruit fly's salivary gland referenced in the question is an example of how chromosomes can be observed and demonstrates the significance of microscopy in cellular biology.