Practice Questions

Somatic chromosome consistency relies on high-fidelity DNA replication during S-phase followed by symmetrical separation of sister chromatids to daughter nuclei during mitosis.

Sub-metacentric chromosomes possess arms of unequal lengths due to sub-median centromeres, making them look like an 'L' during movement. Metacentric forms a 'V', and acrocentric forms a 'J'.

The kinetochore is a complex macromolecular protein structure assembled specifically on the centromeric DNA of each mitotic chromosome to bind spindle microtubules.

The sugar-phosphate backbone of DNA contains repeated phosphate groups that carry negative charges at physiological pH, allowing complementary electrostatic binding to basic histones.

The structural interaction of linker histone H1 with adjacent nucleosomes drives the further compaction of the 10-nm nucleosome strand into a 30-nm helical spiral loop array termed a solenoid.

Euchromatin is the transcriptionally active, loosely organized chromatin form that allows RNA polymerase complexes to access structural gene sequences. Heterochromatin represents tightly packed, silent regions.

A satellite body (or trabant) is a small chromosomal segment separated from the main body of the chromosome by a secondary constriction. Its presence characterizes SAT-chromosomes.

Metacentric chromosomes have a centrally located centromere, creating two arms of approximately equal structural length, taking on a characteristic 'V' shape during anaphase migration.

Histones are highly basic proteins because they contain large proportions of positively charged amino acids, specifically lysine and arginine. This positive charge mediates tight electrostatic interactions with the negatively charged sugar-phosphate backbone of DNA.

Secondary constrictions, also designated as Nucleolar Organizer Regions (NORs), contain specific genetic configurations responsible for transcribing ribosomal RNA and reorganizing the nucleolus.