In eukaryotic organisms — plants, animals and fungi — the major portion of DNA is present in the chromosomes which are well-organised structures and quite different from the prokaryotic counterparts. Besides the chromosomes, mitochondria of both plants and animals and the chloroplasts of green plants also contain DNA. Interesting is the fact that the organization and the nature of the [...]
In this article we will discuss about the organisation of DNA in bacteria. The DNA of bacteria, e.g. E. coli, is a covalently closed circular molecule. It forms the bacterial chromosome, though this chromosome is much simpler in structure and in level of organization than the eukaryotic chromosomes of plants and animals. Also, each bacterial cell normally has a single [...]
Here is an essay on the plant cell. If a thin slice is taken from any part of a plant and observed under a microscope, it is found to be composed of many chambers or compartments resembling the chambers of a honeycomb. Each of these chambers is called a cell. A plant cell has usually an outer firm non-living boundary [...]