Question

If you are given a specimen (from kingdom Animalia), what are the steps that you would follow to classify it?

Answer 1

Hint:- Biological classification is the process by which biologists group organisms based on how similar they are and what features they have in common. Kingdom Animalia comprises eukaryotic, multicellular, heterotrophic organisms commonly called animals. Unlike plants and fungi, animal cells are devoid of a rigid cell wall and are motile beings.

Complete step-by-step solution:- Biologists follow Linnaeus' system of biological classification for all living organisms on earth. This system has seven levels which are Kingdom, Phylum, Class, Order, Family, Genus and Species.
This classification is done on the basis of certain fundamental features that are found in common. It involves the following steps of identification criteria.
First, identify the level of organisation, i.e., cellular, tissue or organ grade of organisation.
Second, check for body symmetry. Classify the organism as radially or bilaterally symmetrical or asymmetrical.
Third, classify on the basis of presence of germ layers i.e., diploblastic or triploblastic condition.
Fourth, identify the presence or absence of a body cavity.
Fifth, classify based on type of coelom development, i.e., acoelom, true coelom or pseudocoelom.
Sixth, look for segmentation of the body.
Seventh, check for the presence or absence of a notochord.
Eight, look for the presence or absence of a vertebral column.

Note:- Coelom is a fluid filled space present between the body wall and digestive tract. The presence or absence of body cavity or coelom plays a very important role in the classification of animals. A true coelom can be categorized as Enterocoelic or Schizocoelic depending on the development of mouth and anus. Organisms having a notochord are classified as chordates and those without a notochord are called non-chordates. A vertebral column is present in higher animals like fishes, amphibians, reptiles, birds and mammals.