Answer: Characteristics: The fins are supported by rays, as the name indicates. In contrast to the cartilaginous fish they have a rigid skeleton. The swim bladder is also a unique feature of most ray-finned fish, enabling them to maintain buoyancy as they move up or down in the water.
Epithelial tissue. This type of tissue is made up of cells that are closely packed and arranged in one or more layers. Epithelial tissues cover internal and external body surfaces. They have a high regenerative capacity.and has many functions including, protection, absorption, secretion, sensation and excretion.
B; Medication to decrease the viscosity of the blood.
The Nucleus,
It stores the DNA and controls the cell