Publication Date

1971

Document Type

Dissertation/Thesis

First Advisor

Abdel-Hameed, Fathi, 1938-||Bennett, Jack (Cecil Jackson)

Degree Name

M.S. (Master of Science)

Department

Department of Biological Sciences

LCSH

Chromosomes||Locusts

Abstract

Thirteen populations of the grasshopper species Melanoplus femur-rubrum were surveyed for B chromosome frequency distribution. Two populations were surveyed eight times during a single season and three times during a single day in an attempt to detect B frequency variations. Several populations were intensively analyzed for variations in B chromosome morphology and activity. Results of these analyses revealed that B frequency variations occur between isolated populations but remain stable for one population between yearly samples, during a single meiotic season and throughout a single day. Four possible types of B chromosomes were described. Both individual and populational differences in B chromosome activity during meiosis were recorded. Chromosome area studies revealed that the area of the X chromosome is significantly reduced at metaphase I when B chromosomes are present in the same cell. No variations in chiasma frequency were found in the populations analyzed. Chromosome arm length studies revealed that the origin of the three major B chromosome types is most likely one of the smallest three autosomes. Several other structural anomalies involving the X and autosomes are described.

Comments

Includes bibliographical references.||Includes illustrations.

Extent

143 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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