Organ system level of organisation is shown by

Options

A. sponges
B. coelenterates
C. diploblastic animals
D. triploblastic animals

Answer

To determine which organisms exhibit the organ system level of organization, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Levels of Organization**:
- Organisms can be organized at different levels: cellular, tissue, organ, and organ system levels.
- The organ system level of organization is characterized by groups of organs that work together to perform complex functions.

2. **Examine the Options**:
- **Sponges (Phylum Porifera)**: These organisms are the most primitive and exhibit a cellular level of organization. They lack true tissues and organs.
- **Cnidarians (Phylum Cnidaria)**: These organisms, such as jellyfish and corals, have a tissue level of organization but do not have true organs or organ systems.
- **Diploblastic Animals**: These animals have two germ layers (ectoderm and endoderm) and show organ level of organization, but not organ systems.
- **Triploblastic Animals**: These organisms have three germ layers (ectoderm, mesoderm, and endoderm). The presence of the mesoderm allows for the development of complex organs and organ systems.

3. **Identify the Correct Option**:
- Among the options, only triploblastic animals, which include humans, fish, and other higher organisms, exhibit the organ system level of organization. This is because they have multiple organs that work together in systems (e.g., circulatory system, digestive system).

4. **Conclusion**:
- Therefore, the correct answer to the question is that the organ system level of organization is shown by **triploblastic animals**.