In some vehicles the retractor â not the latchplate â provides the locking part needed to keep a car seat in place at all times. The purpose of the retractor is to store the excess webbing. These retractors are usually present when a non-locking latchplate (sliding, sewn-on, or dynamic locking) is present.
In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, kernel) is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins such as histones to form chromosomes.The genes within these chromosomes make up the cell's nuclear genome.t contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins such as histones to form chromosomes.
The cytoplasm is not subdivided by membranes into organelles, a lack of compartmentalization that is most evident when we look at the organization of the genetic material. This is an important distinguishing feature of these types of cells. Structure of the Genetic Material. Genetic information in prokaryotic cells is carried on a single circular piece of DNA which is attached to the cell membrane and in direct contact with the cytoplasm. There is no enclosing membrane, so there is no true nucleus, but simply a concentration of DNA known as a nucleoid.