Why is hydra classified under the Cnidaria phylum? The body of Hydra is divided into two layers and has radial symmetry. Their bodies have a cavity called coelenteron, which basically is the main characteristic of Cnidaria animals. That’s why Hydra is classified under the Cnidaria phylum.
What do you mean by nematocyst? Inside the cnidocyte cell, there is a long, narrow, hollow, and twisted thread connected with a thick layered capsule that is called a nematocyst. Nematocyst is formed with protein and phenol and is filled with a toxic liquid named hypnotoxin. Nematocyst is located in Hydra‘s tentacles which helps them … Read more
Why the animals of the subphylum – Urochordata are called sea sequins? The animals of the subphylum Urochordata are mainly sea animals. Some of their species can expel water like a fountain with the help of siphons. For this reason, they are called sea fountains or sequins. The matured animals stay submerged and remain permanently … Read more
What are the unique features of the animals of phylum – Echinodermata? The animals belonging to the phylum – Echinodermata are pentaradially symmetrical which means their body can be divided into 5 or multiple parts. The exoskeleton of the body is full of spikes, spines, and pedicellariae. The body is divided into oral and aboral … Read more
Why grasshopper is placed in the class – Insecta? Grasshopper is placed in the class Insecta because it has an exoskeleton made of chitin, a three-segmented (head, thorax, and abdomen) body, three pairs of jointed legs, compound eyes, and a pair of antenna. These are the main characteristics of the animals of the class – … Read more
Why are the cnidarian animals known as bilayered animals? The embryos of the animals in which there are only layers – ectoderm and endoderm are called bi-layered animals. In between these two layers, there is an acellular jelly-like structure called mesoglea. All the animals of the Cnidaria phylum are bi-layered. For this reason, the cnidarian … Read more
What do you mean by binomial nomenclature? According to the international rule, the combined name which is given to an animal by placing the name of the ‘genus’ first and then the name of the ‘species’ is called binomial nomenclature. In this case, both the words are either in Latin or in modified Latin. For … Read more
What do you mean by ICZN? ICZN (International Commission of Zoological Nomenclature) is an international organization for the nomenclature of animals. This organization makes rules about the nomenclature of animals. Nomenclature is an important process to identify a special animal or animal group.