OBJECTIVE LIFE SCIENCE
MOLECULAR BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Polytene chromosome
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Lampbrush chromosome
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Euchromosome
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Circular chromosome
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Detailed explanation-1: -During the process of polyploidization, chromosomes become multistranded. In Drosophila the degree of polyteny is estimated to be approximately 1024 in salivary gland chromosomes, i.e., about 512 in each homolog.
Detailed explanation-2: -A polytene chromosome is an X-shaped chromosome that is found in Drosophila melanogaster. These chromosomes are composed of euchromatin and heterochromatin. Euchromatin is the gene-rich portion of the chromosome and is responsible for the colour and shape of the chromosome.
Detailed explanation-3: -Polytene chromosomes were first discovered in the 1880s in insects (Balbiani 1881). One of the earliest published examples of polytene chromosomes is of Chironimus salivary gland chromosomes found in Walther Flemming’s 1882 book, Zellsubstanz, Kern, und Zelltheilung (Flemming 1882).