Single circulation is a type of circulatory system found in some organisms where the blood passes through the heart only once in a complete circuit of the body. Among the given options, fishes are the organisms that exhibit single circulation.

Explanation:

What is single circulation?
Single circulation is a type of circulatory system found in some lower vertebrates, where the blood passes through the heart only once in a complete circuit of the body. In this system, blood is pumped from the heart to the gills or lungs for oxygenation and then distributed to the rest of the body.

Fishes and single circulation:
Fishes are the only organisms among the given options that have single circulation. The circulatory system in fishes is relatively simple compared to other vertebrates. It consists of a two-chambered heart, which consists of an atrium and a ventricle.

Circulation in fishes:
1. Oxygenated blood from the gills enters the heart through the atrium.
2. The atrium contracts, pushing the blood into the ventricle.
3. The ventricle then contracts, pumping the oxygenated blood to the rest of the body.
4. Deoxygenated blood from the body is collected in the sinus venosus, which acts as a collecting chamber.
5. The deoxygenated blood is then pumped to the gills for oxygenation.

Advantages and disadvantages of single circulation in fishes:
Advantages:
- Single circulation allows for efficient oxygenation of blood in the gills, as blood flow through the gills is regulated.
- It is a relatively simple and energy-efficient system.

Disadvantages:
- Single circulation system limits the amount of oxygen that can be delivered to the body tissues.
- It may not be suitable for organisms with high metabolic demands, as it restricts the supply of oxygen and nutrients to the tissues.

In conclusion, among the given options, fishes are the organisms that exhibit single circulation. This type of circulatory system allows for efficient oxygenation of blood in the gills and is relatively simple. However, it may not be suitable for organisms with high metabolic demands.