In this article we will discuss about the Structure of a Typical Fish. Fishes are cold blooded animals, typically with backbone, gills and fins. The body of a typical fish comprises the head, trunk and tail. The head bears two eyes, with well developed nictitating membrane, two internal ears, two nostrils which are closed internally (except in lung fishes) and [...]
The upcoming discussion will update you about the difference among the three groups of mammals. Difference # Prototheria: 1. Prototheria is oviparous. 2. Pinna is absent in prototheria.z 3. Prototheria has no nipples (mammae). 4. No marsupial pouch is present in prototheria. 5. in Prototheria, digestive and urinogenital tracts open into a cloaca. Cloaca opens outside through cloaca aperture. 6. [...]
The below mentioned article provides biology notes on Phylum Hemichordata. (Gk. hemi- half, chordate- notochord) Due to some similarities with chordates, some workers considered Hemichordata as a subphylum under phylum chordata. But, on grounds of its general organization, recent scientists, like Vander Horst (1939), Dawyd off (1948), Marcus (1958) and Hyman (1959), have given it the status of a phylum [...]