Actin exists as: 

a globular monomer -G-actin 

a filamentous polymer- F-actin

TLS Online TPP Program

#Id: 482

#Unit 2. Cellular Organization

Interphase chromatin remain attached to nuclear wall proteins via matrix attachment regions (MARs) or matrix attachment DNA sequences

TLS Online TPP Program

#Id: 483

#Unit 2. Cellular Organization

Interphase chromosomes occupy chromosome territories in the nucleus and are not entangled with each other

TLS Online TPP Program

#Id: 484

#Unit 2. Cellular Organization

Heterochromatic regions, silenced genes, and gene-sparse regions of chromosomes are typically localized to the nuclear periphery.

TLS Online TPP Program

#Id: 485

#Unit 2. Cellular Organization

Active genes/euchromatin 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: 486

#Unit 2. Cellular Organization

MARs are AT rich heterochromatic regions which contains cis-acting sites that regulate transcription, 5’ introns, and a recognition site for topoisomerase II is usually present in the MAR.

TLS Online TPP Program

#Id: 487

#Unit 2. Cellular Organization

Presence of topoisomerase II binding sites shows high degree of negative supercoiling is usually present in the MAR.