Balanoglossus It is a marine water-dwelling acorn worm (Enteropneusta). Blanoglossus cannot survive in freshwater. It belongs to hemichordates. it is an “evolutionary link” between invertebrates and vertebrates. Discovered by J.F. Eschscholtz in 1825 in Mashail Island. He described it as a worm-like holothurian. Kowalewski (1865) discovered the gill – slits Read more…
Subphylum – Urochordata (Tunicates) Subphylum – Urochordata: Position of Urochordates- Lamarck placed Tunicata in between radiate and Vermes in his system of classification. Later they were kept in Mollusca. Kowalevsky kept them in chordates in 1866. The Urochordates are also known as tunicates. These are commonly known as “sea squirts”. Read more…
Amphioxus (Lancelet) The Amphioxus also known as lancelet, Consisting of 30 to 35 species of “fish-like” chordates. Branchiostoma is one of the few living genera of lancelets. It is the type genus of the family Branchiostomidae. The lancelets are believed to be related to Pikaia (530-million-year-old) fossils. The first representative Read more…
Blood Groups: Types of Blood Grouping The blood is classified on the basis of the presence and absence of antibodies and inherited antigenic substances on the surface of RBCs (red blood cells). The antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. Blood types are Read more…
Zika Virus Why in News? Few Zika Virus Infection cases have been reported in one of the states in the Republic of INDIA and that is Kerala. As of now today in Kerala 15th Zika Virus Infectious cases have been reported. Due to that all the Border sharing states of Read more…
Blood – definition, composition, and Function Blood is the fluid connective tissue consisting of a fluid matrix, plasma, and formed elements. It is a fluid found in humans and other organisms that transport necessary substances such as nutrients and oxygen to the cells, and it carries away metabolic waste from Read more…
Nervous Tissue The nervous tissues are specialized with no intercellular space. They are found in the brain, spinal cord, and nerves. These are the main components of the nervous system. The nervous system function to regulate and controls bodily functions. The nervous system consisting two parts- Central Nervous System and Read more…
Muscular Tissue The Muscle tissue is soft and it makes different types of muscles in animals, which gives the ability of muscles to contract. Muscular tissues are also referred to as myopropulsive tissue. Muscular tissues are formed during embryonic development by the process of myogenesis. The muscle tissues are mesodermal Read more…
Connective tissues The term connective tissue was introduced in 1830 by Johannes Peter Muller. The tissue was already recognized as a distinct class in the 18th century Connective tissues are the most abundant and widely distributed tissues of complex animals. These are mesodermal in origin. They perform the special function Read more…
Epithelial tissue The term “epithelium” was introduced by Frederic Ruysch in 1703. Epithelium tissue is made up of one or more layers of cells that are compactly arranged with a little intracellular matrix. Important features of Epithelial tissue: The Epithelial tissues line the external surfaces of organs and blood vessels Read more…