Prepare a table showing respiratory organs in various groups of animals (both non-chordates and chordates)?
Answers
Answer:
Explanation:
Classification of Animal Kingdom
The science of classifying organisms is called taxonomy. Every species discovered so far are classified into five kingdoms – one among them is Kingdom Animalia or Animal kingdom. The members of kingdom Animalia are further classified into different Phyla, Class, Order, Family, and Genus based on certain identifiable characteristic features.
One of the most fundamental forms of classification of animals is the presence or absence of the notochord. Hence, two major groups exist, namely: Chordates and Non-chordates.
Non-chordates and the Chordates
The notochord is a flexible rod made out of a material similar to cartilage. If an animal has a notochord during any stage of its life, it is classified as a chordate. Contrary to popular belief, chordates do not exclusively include vertebrates.
There are invertebrates that possess a notochord during some point in their lives and hence, are classified as chordates. Thus all vertebrates are chordates but not all chordates are vertebrates.
They are cylindrical, triploblastic, coelomate, or pseudocoelomate animals.
Respiration in these animals takes place through gills, trachea or body surface.
Most of the times, sexes cannot be distinguished among the members.
Modes of reproduction involve sexual and asexual
Fertilization is external, though internal fertilization also occurs in some species.
The body of non-chordates generally includes an open type of circulatory system.
Chordates
Chordates are animals characterized by the presence of notochord at some stage during their development. Members possess a hollow nerve cord and pharyngeal gill slits. The other general characteristic features of Chordates are as follows:
It is also referred to as Tunicata which are marine animals. The body of these animals is surrounded by a leathery covering (similar to a tunic, hence the name). Larvae are free-swimming, the notochord is present only in the tail of larvae and after settling on the seabed, they get transformed into sessile adults. They are generally hermaphrodites.
Examples include – Ascidians, Doliolum, Oikopleura, etc.
Subphylum – Cephalochordata
It mainly consists of small, fish-like marine animals in which the notochord is extended along the entire body. The animals also have pharynx, which is large with numerous gill- slits. Members of this subphylum have separate sexes.
Example include – Amphioxus or lancelet.
Subphylum – Vertebrata
In this subphylum, the notochord is present in the embryonic stages and is replaced by a vertebral column in the adult. They have 2, 3 or 4 chambered heart, paired appendages for locomotion and kidneys for excretion or osmoregulation.
Vertebrates Classification
The subphylum Vertebrata is divided into five classes of vertebrates. These five classes of vertebrates comprise of all the species of animals and have developed vertebral column as well as an internal skeleton.
There are over 66,000 species of vertebrates identified under phylum Chordata till date. The defining feature of vertebrates is that their bodies are bilaterally symmetrical, coelomic, triploblastic, and with complex differentiation of body tissues and organs.
Mammalia
Class Pisces (Fishes)
They are aquatic animals, having a streamlined body and a pair of fins which are used for propulsion and movement. Furthermore, fish are cold-blooded, but the discovery of a new species in 2015 has changed this perception. The opah or the moon-fish is a fully warm-blooded fish capable of regulating its body temperature.
Endoskeleton may be cartilaginous or bony and respiration occurs through gills. They do not possess eyelids because the surface of the eye is to be kept moist all the time.
Examples of Class Pisces includes dogfish and Rohu.
Read More: Pisces
Class Amphibia
They usually comprise those organisms which are cold-blooded and require an aquatic habitat to lay eggs. These organisms are mainly characterized by the two pairs of limbs, smooth and moist skin for respiration. They also possess protruding eyes which are protected by usually more than one pair of eyelids. (Frogs have 3).
Examples of Class Amphibia are frog, toad, and salamander.