Question

Compare the metabolic potential (ability to burn organic molecules rapidly) of an oyster with an open circulatory system, a fly with an open circulatory system + a tracheal system, and a racer (a type of snake) with a closed circulatory system. In the fly, which needs are met by the circulatory system, and which are met by the tracheal system?

Answer 1

Oyesters exchange gases by using their skin and siphons via diffusion and it mixes with their blood. Now this blood is 1st pumped by their heart through some large vessels and finally enters the body cavity where it passes over the cells. Now in this kind of circulatory system the blood flow is alow and so metabolic rate of the cells also very slow. Thus the oyesters move at such slow pace to conserve their energy.

A fly also have a open circulatory system i.e its haemolymph(the internal body fluid) is not confined to a closed vessel. After heart via some vessels it is released into the body cavity or hemocoel where it comes in contact with the body cells. But its gaseous exchange system is improved by the tracheal system which have air sacs which stores gases and can exchange the gases with the haemolymph by using pressure. Now because of this reason there is more oxygen available to each fly cells as compared to oyesters. So this total system have higher metabolic potential than oyester's.

Now in a racer snake as a longer body and moves with a very high speed so they require more energy. They have a closed circulatory system, meaning their blood moves only through blood vessels. Because of this the blood moves through the vessels at a much higher pressure and thus speed. This enables the blood to reach the furthest corner of the snakes bodylength. Now the snake also have haemoglobin which carry oxygen to the body cells, this also increases the supply of oxygen to each cell. So the racer snake has a much higher metabolic rate than both the fly and oyester.

2nd part:

In fly , circulatory system supply oxygen and nutrients to each cell of the body and takes out carbon di oxide and waste material of the cells and purifies them via kidney. It helps to cause gaseous exchange in the bodycells where direct gaseous exchage through trache is not possible.

Tracheal system in fly is for storing gases and exchange of gases with the haemolymph(the internal body fluid) and air.