describe the different levels of organisation of body of animals with an example for each
Answers
Answer:
The structural organisation in animals starts from the smallest fundamental unit – the cell. And a group of cells that perform a similar function forms tissues. When tissues group together to perform specific functions, they form organs.
Explanation:
Based on the patterns cellular organization, levels of organization in animals are classified in to:
The cellular level of organization: Animals with this type of cell organization have cells arranged in the form of loose cell aggregates. This type of organization can be observed in sponges.
Tissue level of organization: The cells of the animals show divisions in cell activities. The cells which perform the same functions are arranged as tissues. Example: Coelenterates.
Organ level of organization: Tissues in a certain group of animals that have the same function are grouped to form an organ. Each organ has a specific function. Example: Platyhelminthes
Organ system level of organization: In animals where organs have associated to form functional systems where each system is concerned with a certain physiological function are observed to exhibit organ system level of organization. Example: Annelids, Arthropods, Echinoderms, Mollusks, and Chordates.
Level of body organisation :- It's a classification in which animals are classified on the basis of cells. It can be further classified into five types.
(i) Protoplasmic level :- In this unicellular body does all the vital biological functions of the body. Protozoans are included in this category.
(ii) Cellular level :- Such animals in which functions are performed in the cell level. In most of the sponges cellular level organisation is present.
(iii) Tissue level :- In this cells are arranged to perform the biological activities into the tissues. Coelenterates and ctenophores are included in this.
(iv) Organ level :- When there are number of tissues and they all are grouped together to form organs. In platyhelminthes organ level organisation is found.
(V) Organ system level :- It is seen in the higher animals, in which different organs combines to form organ system. Annelida, Arthropod, Molluscs, Aschelminthes, Ecinodermata and chordates come in this category.