The following points highlight the three main classes of protein fibers in cytoskeleton. The classes are: 1. Microtubules 2. Actin Filaments 3. Intermediate Filaments. Protein Fibers in Cytoskeleton: Class # 1. Microtubules: Microtubules are long thread-like structures measuring about 25 nm in diameter; their length varies up to several millimeters. Microtubules have the following two main properties: (i) Long and [...]
In this article we will discuss about the replication of eukaryotic chromosome. Taylor in 1958 used radioactive thymidine (3H-thymidine) to label Viciafaba root tip chromosomes. He showed that the chromosomes replicated in a semiconservative manner, and proposed that each chromatid was made up of a single DNA molecule. Thus each sister chromatid is composed of one of the two progeny [...]
In this article we will discuss about the replication of genetic RNA. Several viruses and bacteriophages contain single- or double-stranded RNA as their genetic material (Table 3.1). Replication of these RNA chromosomes occurs in the host cytoplasm following one of the two modes given below: (i) Direct use of RNA template for RNA synthesis (RNA RNA) by the enzyme -'RNA [...]