Genome pathomorphology

Select true sentence about the Human Genome Project:

When was the human nuclear genome fully sequenced?

Human chromatin is composed of:

Select a correct sentence on human genome

How long is human DNA in a single somatic cell?

The human genome is approximately 3 billion base pairs and contains about 20, 000 protein coding genes.

Nucleosomes are the structural and functional units of chromatin

The nuclear matrix mediates the formation of DNA loop domains that are anchored to S/MAR

Interphase is a time in the cell cycle when the cell rests between mitosis and is transcriptionally inactive.

Heterochromatin is condensed, transcriptionally inactive chromatin

The terms heterochromatin and euchromatin refer to states of compaction and transcriptional potential.

The nucleosomes are separated by 10 to 90 bp stretches of histone H1 bound linker DNA.

The human genome is organized into loop domains attached at their bases to the nuclear scaffold/matrix by S/MARs

Chromatin in the interphase nucleus are categorized into euchromatin and heterochromatin, based on the physical compaction state, gene density, and transcriptional activity

The structure of chromatin determines the accessibility of DNA to transcriptional machinery; thus, it is closely related to gene activity

Nucleosome is a structural unit of chromatin composed of a positively charged protein core of eight histone proteins wrapped by 1.7 turns of DNA 147 bp in length.

Metaphase chromosomes are so highly condensed that their morphology can be studied using the light microscope

Chromatin is just a passive platform for the storage of genetic information.

Dynamic mode of packing and unpacking chromatin is intimately linked to the ability of the genome to specifically complex with both histones and non-histone proteins

As a first level of compaction, DNA segments of 147 bp are wrapped in 1.7 left-handed turns around histone octamers forming the nucleosome core, each having a diameter of 10-11 nm

MicroRNAs are a family of small non-coding RNAs that regulate a wide array of biological processes including carcinogenesis

S/MARs are DNA elements that serve to compartmentalize the chromatin into structural and functional domains

The nuclear matrix interacts with chromatin via specialized DNA sequences called S/MAR.

Some of the S/MAR-binding proteins are dramatically deregulated in tumor cells

Anchorage of S/MARs to nuclear matrix is known to play a dual role. (i) Structural role to maintain the higher order chromatin confirmation
(ii) functional role in regulation of DNA replication and gene expression.

There is currently only one model of chromatin organization.

The nuclear matrix consists of both nuclear proteins and RNA

The ultimate condensation that occurs during the formation of metaphase chromosomes during mitosis facilitates the faithful segregation of the genetic material into daughter cells.

The main epigenetic mechanisms include DNA methylation, histone modifications, and regulation by non-coding RNAs

Epigenetics refers to heritable and non-heritable traits without changing the DNA sequence

Epigenetic control operates on three major levels, i.e., on DNA, histones, and nucleosomes

MicroRNAs are endogenous, small non-coding RNAs that function in regulation of gene expression.

The epigenetic alteration is a well-known feature in human cancer.

MiRNA may function as either tumor suppressor or oncogene under certain circumstances.

Circulating miRNAs are becoming candidates of emerging non-invasive cellular and molecular biomarkers of cancer.

The most commonly used staining system in pathomorphology is called H&E

Hematoxylin stains cell nuclei red.