Related Experiment Video
Updated: Jul 17, 2026

Establishment and Maintenance of Gnotobiotic American Cockroaches (Periplaneta americana)
Published on: May 28, 2021
Alternate-2 disjunction in the german cockroach
1Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061.
Abstract:
The evidence in support of two types of alternate disjunction in translocation heterozygotes from the German cockroach, Blattella germanica (L.), is reviewed. When unique cytomorphological features occur in the translocation figure, the two types of alternate disjunction are identifiable regardless of the angle of observation. Photographs supporting this contention are presented for alternate-1 and alternate-2 disjunction in T(7;12)/7;12 . Other evidence in support of the existence of alternate-2 disjunction is also presented.
Related Concept Videos
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Dosage Compensation
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
Null and Alternative Hypotheses
The null hypothesis, denoted by H0 is a statement of no difference between the variables—they are not related. This can often be considered the status quo. As a result if you cannot accept the null, it requires some action.
The alternative hypothesis, denoted by H1 or Ha, is a claim about the population that is...

