Viral and Bacterial Chromosomes
The DNA conformation of most bacterial chromosomes, in which the DNA molecule lacks free ends
Circular DNA
The region in genes absent in mtDNA.
Introns
When polytene chromosomes are stained and viewed under a microscope, they display a highly specific and reproducible pattern consisting of these alternating features.
Bands and Interbands
These are positively charged proteins that package eukaryotic DNA into chromatin
Histones
This fraction of eukaryotic DNA, which separates as an additional peak during density gradient centrifugation, consists of highly repetitive tandem arrays located in heterochromatic regions.
Satellite DNA
These bacterial DNA-binding proteins facilitate folding and bending of bacterial DNA
HU and H-NS proteins
The origin of both mtDNA and cpDNA.
Maternal Cytoplasm
Polytene chromosomes are visible during this specific, non-dividing stage of the cell cycle.
Interphase
This is responsible for the stacking of nucleosomes into solenoids.
H1 Histone
These evolutionary remnants of duplicated genes are noncoding and typically untranscribed due to disabling mutations like insertions and deletions.
Pseudogenes
The compact DNA structure formed when underwound bacterial DNA twists upon itself
Supercoiling
This foundational evolutionary theory explains why cpDNA resembles cyanobacteria and why both organelles have their own independent genomes.
Endosymbiotic Theory
Localized uncoiled regions on polytene chromosomes that indicate active high-level gene expression are called puffs, or by this alternative specific term named after their discoverer.
Balbiani rings
The interest of chromatin remodelling
Histone Tails
This specific variant histone replaces normal H3 in centromeric heterochromatin and is crucial for assembling the kinetochore.
CENP-A
The enzyme that cuts one or both strands, changes the degree of DNA unwinding, and reseals the DNA strands
Topoisomerase
mtDNA Replication is dependent on enzymes encoded from this.
Nuclear DNA
These specific visual features of polytene chromosomes represent the tightly wound, structurally permanent regions where genes are mostly inactive.
Dark bands
This influences adjacent euchromatin to become inert from translocated heterochromatin.
Position Effect
Making up more than 5% of the human genome, this prominent family of SINEs is 200 to 300 base pairs long and can actively transpose within the genome.
The type of genetic material present in Tobacco mosaic virus
RNA
Chloroplast DNA shares a striking structural similarity to the DNA of this specific type of bacteria.
Cyanobacteria
Polytene chromosomes are easily found and studied in the salivary glands of larvae belonging to this insect order.
Diptera
This is responsible for acetylation
Histone Acetyltransferase
In humans, the most common type of microsatellite or Short Tandem Repeat (STR) consists of repeating units of this specific dinucleotide.
(CA)n