Question

In karyogram, sex chromosomes should be placed at the end, but the exception is-
A. Drosophila
B. Homo sapiens
C. Pisum
D. Ginkgo

Answer 1

Hint: A karyogram is defined as the graphical representation of a karyotype. The chromosome count of an organism, location of centromeres, banding patterns, and paired homologous pairs arranged according to size are represented by a karyotype.

Complete answer: A karyogram is a tool used to represent chromosomes, making it simple to visualize the way chromosomes are arranged in the image. They are organized into homologous pairs, each of which is arranged in order of size, from largest to smallest. Each chromosome is matched with its homologous chromosome, even though it carries different alleles, and is an exact match in size and structure. Such pairs of autosomal chromosomes are numbered according to size. The sex chromosomes, X and Y, are put at the top, even though they are smaller in number. Karyograms aid in the study of chromosomal aberrations, taxonomic relationships, and events in evolution.
 

The common fruit fly or vinegar fly is also known as Drosophila. As well as autosomes, Drosophila flies have both X and Y chromosomes. The Y chromosome, unlike humans, does not impart maleness on them, but rather encodes genes required for sperm development. Their sex is determined by the ratio of autosomes and X chromosomes.
Hence, the correct answer is option A, i.e., Drosophila.

Note: Each Drosophila cell, independently of the rest of the organism, determines whether to be male or female, resulting in the occasional occurrence of gynandromorphs, i.e. An organism that incorporates the features of both men and women. Among the first species used for genetic research was Drosophila.