Chloroplasts are double membraned rod-like oval or spherical cell organelles in the cytoplasm of most plant cells that help in photosynthesis. It is a green plastid containing chlorophylls. Animal cells normally lack plastids(all forms of plastids including chloroplasts). Several unicellular…
Mitochondria are the rod-shaped, ovoid, or thread-like, scattered minute particles in all aerobic cells of higher animals and plants. These are also present in algae, protozoa, and fungi. Bacterial cells, however, do not have mitochondria. They are associated with cellular…
Ribosomes are membraneless, small, sub-spherical ribonucleoprotein particles. They are often found connected to the outside of the endoplasmic reticulum and nucleus. Ribosomes also occur freely in the cytoplasm (cytoplasmic matrix), chloroplasts, and mitochondria. In 1943, A. Claude has first isolated…
Lysosomes are tiny vascular membrane-bound vesicles involved in intracellular digestion. They contain a variety of hydrolytic enzymes that remain active under acidic conditions. Greek words “Lysis = digestive or break down, and soma = body“. During electron microscopic studies in…
The Golgi apparatus or the Golgi body or Golgi complex or simply the Golgi is a complex cytoplasmic structure having relation to cellular secretion. Which consists of vesicles and vacuoles, with smooth cisternae and a network of tubules. In 1898,…
Sterilization is the complete eradication of microorganisms (fungi, bacteria, and viruses) present on the surface of any material. The microorganisms can be removed or destroyed from the definite materials (seeds, leaves, root pieces, stem pieces) by using sterilization techniques. Objective…
The Eukaryotic cell is the most advanced type of cell which is present in both animals and plants. Dougherty (1957) has divided cells into two types (based on the organization in the nucleus of the cell) – The Prokaryotic cell…
The mesokaryotic cell is the intermediate cell of the Prokaryotic cell and the Eukaryotic cell. Dodge has first used the term mesokaryotic in 1966 for the cell that contains an intermediate nucleus (both eukaryotic and prokaryotic characters are present). Although…
In 1957 Dougherty has divided cells into two types based on the organization in the nucleus of the cell. One is a prokaryotic cell (primitive cell) and the other is a Eukaryotic cell (ideal cell). Prokaryotic cells are the most…
Phylum Echinodermata represents the most advanced invertebrate phylum closer to the chordates. They vary substantially in size which may range from 1 cm to about 2 m in length. In 1734 Jacob Klein has coined the name Echinodermata. The name…