Question

Point at which polytene chromosomes gets attached is
A. Centriole
B. Chromocenter
C. Chromosome
D. Centromere.

Answer 1

Hint:Polytene chromosomes contain non-separated multiple copies of replica DNA. Chromocenter is a densely stained heterochromatic region present in the nucleus of few cells.

Complete answer:
To answer this question, first, we need to know about the polytene chromosomes. Polytene chromosomes are chromosomes which contain thousands of DNA strands that are present within the salivary glands cells of fruit flies or midges. They occur when repeated rounds of DNA replication without cell division produces a large chromosome. Thus polytene chromosomes produce when numerous rounds of replication generate multiple sister chromatids which stay fused together.
Now, let us find the solution from the option.
Centriole is cellular organelle in paired form that functions in the organization of the mitotic spindle during the period cell division in eukaryotic cells.
Chromocenter is the end where polytene chromosomes are visible to be linked together.
Chromomere is a small aligned granule structure that appears on a chromosome during the prophase stage of mitosis and meiosis.
Centromere is a specific area on every chromatid to which kinetochores and sister chromatids are linked.

Thus, the correct option is B. i.e. Chromocenter.

Note:Polytene chromosomes, at interphase, are seen to have distinct thick and thin banding patterns. These patterns were originally used to help map chromosomes, identify small chromosome mutations, and in taxonomic identification. They are now used to study the function of genes in transcription.