Question

State various levels of organization found in the animal kingdom.

Answer 1

Hint: An organism is made up of four levels of the organization. The cell is the building block of all the organisms. In an organism the division of labour occurs throughout the organization. Each component of the organization performs a particular function so that it can maintain the sustainability of an organism.

Complete answer:
An organization means an orderly arrangement. The cell is the building block of an organism. Many specialized cells are organized to form a tissue, many tissues together form an organ, many organs and organ- system, and finally many organ- systems an organism.
Based on how cells are arranged in the body of animals following four levels of organization seen are: - The cellular level of organization - Tissue level of organization - Organ level of organization - Organ- system of organization
The cellular level of organization: Cells are the basic unit of life and perform vital functions of an organism. The cells are arranged as loose cell aggregates but they don’t form any tissue. These levels are exhibited by Poriferans whose bodies are made up of loose aggregates of cells.
Tissue level of organization: This level is somewhat higher and complex to the cellular level in which the cells perform the same function or the structure and are arranged to form tissues. The tissues perform the various basic functions of animals. This level of organization is seen in coelenterates and ctenophores.
Organ level of organization: When tissues are grouped to form organs. Here each organ is specialized for a particular function. This level of organization is seen in Platyhelminthes.
Organ- system level of organization: In higher animals, organs are associated to form functional systems, and each system is concerned with a specific physiological function. For example, the stomach, intestine, gallbladder, etc. unite to perform digestion.
Different organ systems are exhibited by aschelminthes to chordates.

Note:
- Some division of labor is still seen among the cells in Porifera. - First time in the animal kingdom the tissue level of the organization is seen in coelenterates. - Some organ systems are also present in Platyhelminthes. - Arthropods shed a chitinous exoskeleton for allowing the growth and development of the body to give room/space for the growing organs.