In this article we will discuss about the Structure of Cyanobacteria (Blue Green Algae). Blue-green algae are the most primitive organisms in the plant kingdom and show typical prokaryotic organization (Fig. 1.13). A typical cell of blue-green algae is composed of the following components: 1. Outer cellular covering. 2. Cytoplasm. 3. Nucleic material. 1. Outer Cellular Covering: The outer covering [...]
In this article we will discuss about the Physicochemical Organization of Chromosome. The major chemical components of the chromosomes are DNA, proteins (histones and non-histones) and small amount of RNA. Besides these, calcium and some other minerals are also present. Histones are basic proteins that are charged positively at neutral pH. Non-histone proteins are acidic. Histones are small proteins containing [...]
The following points highlight the three special types of chromosomes. The types are: 1. Polytene Chromsomes or Salivary Gland Chromosomes 2. Lampbrush Chromosomes 3. Prokaryotic Nucleoids. Type # 1. Polytene Chromsomes or Salivary Gland Chromosomes: The giant chromosomes were first observed in the cells of salivary glands, gut, trachea and other body parts of dipteran insects by E.G. Balbiani in [...]