The turtle's heart consists of three chambers, their atrium are completely divided while their ventricles are incompletely divided. The structure of the turtle's circulatory system allows the complete separation of oxygenated and deoxygenated blood. This makes the blood circulation of the turtle flexible.
D) stimulus because it is something external that we REACT to, or something that provokes a response
Some samples are transparent, or very difficult to see, therefore, they are stained in order to be seen more clearly and easier to work with.
During eye surgery, the clear layer of the eye is stained to be easily extracted, if it was clear then the surgeon might cut the eye instead of just the layer.
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