Cells are what make up the body. There are, in fact, billions of these cells that serve as the basic structural and functional unit of all kinds of organisms.
Inside each cell, you’ll find a nucleus where the chromatin is found. The main composition of chromatin is deoxyribonucleic acid or DNA and other types of protein. The role of chromatin is to bundle DNA into more manageable volumes so they fit in the cell. Chromatin is also what makes the DNA stronger in order for meiosis and mitosis to happen. Furthermore, chromatin controls the DNA’s expression as well as gene replication, and prevents damage to the DNA.
Chromatin has two types: euchromatin and heterochromatin.
Euchromatin, which is composed of lightly packed material, is often found in the inner body of the nucleus. It is rich in the concentration of genes and is generally under active transcription. Euchromatin, where a high frequency of chromosomal crossing over takes place, makes up around 90 percent of the human genome. Found in both prokaryotes and eukaryotes, euchromatin appears to have light-colored bands when stained and viewed under an optical microscope. Euchromatin regions also appear as loops with about 40 to 100 kb regions of DNA inside it. The chromatin fiber in euchromatin is around 30 nm in diameter.
Heterochromatin, which is composed of tightly packed material, is often found near the edge of the nucleus. The main roles of heterochromatin include the protection of the integrity of the chromosome and the regulation of the gene. The compact nature of heterochromatin prevents the crossover of chromosomes and other genetic events, which is why this type of chromatin is considered inactive both genetically and transcriptionally. Heterochromatin has two types: facultative heterochromatin and constitutive heterochromatin.
Facultative heterochromatin is not a fixed attribute of the nucleus because it consists of the genome’s inactive genes. These genes can be inactive either during some periods or in some cells. On the other hand, constitutive heterochromatin has no genes inside the genome. A fixed attribute of the nucleus, it keeps its compact structure even during the cell’s interphase.
Summary of differences:
Euchromatin and heterochromatin are the two types of chromatin, the structure that contain a chromosome’s DNA strand. The structure, function, transcription, and replication properties are the major areas euchromatin and heterochromatin differ in.
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