In this article we will discuss about some cytological slides and specimen. 1. B-Chromosome or Supernumerary Chromosome: i. The nuclei of some animals or plants contain one or more chromosomes in addition to normal chromosomes. These additional chromosomes are called B-chromosomes or supernumerary chromosomes. ii. First described by Wilson in 1905 in Metapodius, an insect, these chromosomes have now been [...]
The following points highlight the six main cell organelles of protoplasm. The cell organelles are: 1. Chloroplast 2. Mitochondria 3. Golgi Apparatus 4. Nucleus 5. Endoplasmic Reticulum 6. DNA Model. Cell Organelle # 1. Chloroplast: 1. Chloroplasts (Figs. 18, 19), responsible for the photosynthesis of the plants, are the characteristic features of the cells of green plants. 2. Around the [...]
In this article we will discuss about the Subject Matter and Classification of Plastids: Subject Matter of Plastids: Plastids are unique and discrete cytoplasmic organelles found in the cells of most of the plants and certain unicellular organisms particularly protozoa, but not in the cells of higher animals. Although Comparethi (1791) noticed the presence of green granules and Sacks (1865) [...]