Natural gas is a fossil fuel used as a source of energy for heating, cooking, and electricity generation. It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals. Fossil fuel based natural gas is a non-renewable resource.
Definition: A chromosome is a long, stringy aggregate of genes that carries heredity information and is formed from condensed chromatin. Chromatin is composed of DNA and proteins that are tightly packed together to form chromatin fibers. Condensed chromatin fibers form chromosomes.
The DNA in the centromere region of a chromosome is composed of tightly packed chromatin known as heterochromatin. Heterochromatin is very condensed and is therefore not transcribed. Due to its heterochromatin composition, the centromere region stains more darkly with dyes than the other regions of a chromosome.