Zoology notes covering animal diversity, anatomy, physiology, classification, development, evolution, ecology, behaviour, reproduction, and major invertebrate and vertebrate groups.
Submandibular gland is the second largest paired salivary gland of human body. It is about walnut size and its weight is about 7 to 15 gram. It is present in the submandibular triangle of neck, just below the lower border of mandible.
Digastric muscle is a small suprahyoid muscle present in the neck below the lower jaw. It is an important muscle because it helps in movement of mandible, hyoid bone and larynx. The name digastric means “two bellies”. So this muscle has two parts, anterior belly and posterior belly. These two bellies are joined in the
Nervous system is a complex controlling and coordinating system of the body. It receives stimulus, processes the informations and gives response through muscles and glands. Human nervous system is a highly complex biological network of the human body. It is responsible for coordinating body functions, receiving sensory informations and producing different body responses. It has
What is Cyclops? Cyclops is a genus of small freshwater crustaceans which belongs to the subclass Copepoda. It is commonly referred to as water flea due to its small size and free swimming nature. It is named after the one-eyed giants of Greek mythology as a single median eye is present at the centre of
Fish locomotion is referred to as the movement of fish in water with the help of body muscles and fins. It is the process by which fish generate force against water to move from one place to another. This movement is carried out mainly for feeding, escaping from predators and migration. It is controlled by
What is Speciation? Speciation is the evolutionary process by which new species are formed from a pre-existing species. It is the process where a single ancestral population is gradually divided into two or more distinct species. This process occurs when population of a species becomes isolated from each other and the gene flow between them
An egg is a biological structure which contains the female gamete and after fertilization it carries the developing embryo. It is an organic vessel that provides protection and nourishment to the embryo till hatching or birth. The major internal component of egg is yolk (vitellin) which acts as reserve food material and supplying energy for
Phylum Nemathelminthes is a group of worm-like animals which was earlier used in classification and also referred to as Aschelminthes. It includes unsegmented, bilaterally symmetrical and triploblastic animals. These organisms are elongated and cylindrical in shape and the body is tapering at both ends. Because of this shape they are commonly called roundworms or threadworms.
Protochordate larvae is the juvenile stage found in lower chordates, and it is seen in members of Urochordata and Cephalochordata. It is the stage where the animal shows the typical chordate features very clearly. It is the notochord, dorsal hollow nerve cord, pharyngeal slits, and the post-anal tail that appear in this larval period. It
Kingdom Protista is described as a group of eukaryotic organisms which is neither plant nor animal nor fungus. It is the group that consists of organisms having a true nucleus and other membrane-bound organelles, and it is considered as the most diverse group among the eukaryotes. It is the historical classification used to place all
