When blood is actively ejected from the atrium to the ventricle through the open AV valves. The corresponding “blip” in ventricular pressure reflects this additional volume added to the ventricle from atrial systole.

TLS Online TPP Program

#Id: 4020

#Unit 2. Cellular Organization

Local genome alteration, termed kataegis involves activation-induced deaminase (AID)

Chromothripsis entire chromosomes or large parts thereof are shattered (thripsis in Greek means “shattering”) and stitched together again in what appears to be a random manner, leading to dozens or sometimes even hundreds of rearrangements.

TLS Online TPP Program

#Id: 4021

#Unit 2. Cellular Organization

Active genes are often found at the borders of chromosome territories, and active genes from several chromosomes may cluster in inter-chromosomal territories that are enriched in transcription machinery.

TLS Online TPP Program

#Id: 4023

#Unit 2. Cellular Organization

In most regions, the fibers are much less densely packed than in the mitotic chromosome. This material is called euchromatin. It has a relatively dispersed appearance in the nucleus and occupies most of the nuclear region.

TLS Online TPP Program

#Id: 4024

#Unit 2. Cellular Organization

Some regions of chromatin are very densely packed with fibers, displaying a condition comparable to that of the chromosome at mitosis. This material is called heterochromatin.

TLS Online TPP Program

#Id: 4033

#Unit 2. Cellular Organization

In some cases, the various heterochromatic regions, especially those associated with centromeres, aggregate into a densely staining chromocenter.

The common form of heterochromatin that always remains heterochromatic is called constitutive heterochromatin. 

It is permanently condensed. 

It replicates late in S phase and has a reduced frequency of genetic recombination relative to euchromatic gene rich areas of the genome.

TLS Online TPP Program

#Id: 4042

#Unit 2. Cellular Organization

In contrast, there is another category of heterochromatin, called facultative heterochromatin, in which regions of euchromatin are converted to a heterochromatic state.