Prokaryotic Cell: Definition, Features, Structure, Examples
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…
Zoology
Read MoreProkaryotic Cell: Definition, Features, Structure, Examples
Echinodermata: Definition, Characteristics, Classification, Examples
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…
Mollusca: Definition, Characteristics, Examples
Phylum Mollusca is the second largest invertebrate phylum containing more than 90000 described living species after phylum Arthropoda. Johnston has first coined the name Mollusca in 1650. Although Aristotle was…
Arthropoda: Definition, Characteristics, Examples
In the phylum Arthropoda, there is the most number of animal species. The phylum Arthropoda contains more than 1079290 known species like Apis, Laccifer, Millipede, Palaemon, etc. The name Arthropoda…
Annelida: Definition, Characteristics, Examples
The phylum Annelida is a group of organisms having ring-shaped segments. The term Annelida is derived from the Latin word; ” Annulus = ring “ There are more than 15000…
Aschelminthes: Definition, Characteristics, Examples
Aschelminthes is considered a superphylum, which includes many phyla. The term Aschelminthes was first introduced by Grobben in 1910. Earlier in 1859, Gegenbour was named Nemathelminthes for this phylum. So,…
Platyhelminthes: Definition, Characteristics, Examples
In 1859 the scientist Gegenbaur proposed the name phylum platyhelminthes. Originally the animals of this group were placed in the taxon vermis by Linnaeus in 1735 along with other worms.…
Ctenophora: Definition, Characteristics, Examples
Phylum Ctenophora and Phylum Cnidaria were in one phylum (phylum Coelenterata) in the early days. Later Coelenterata was divided into two separate phyla one is Cnidaria and the other is…
Cnidaria: Definition, Characteristics, Examples
Phylum Cnidaria is the group of multicellular animals belonging to the sub-kingdom of Enterozao. According to tissue differentiation, the animals of this group are two types diploblastic and triploblastic. In…
Porifera: Definition, Characteristics, Examples
The scientist R. Grant used the term phylum-Porifera for the first time in 1836. Phylum-Porifera belongs to the sub-kingdom Parazoa. Although all the animals of Porifera are multicellular, the cells…