Dr. Yusuf also discusses this topic in his valuable articles, where he says:

"The function of breathing, which we find in all living creatures from the lowest to the highest, is an amazing process. In all cases it is simply the process of oxidization, i.e., the union of oxygen with nutrients in the cells of the body, which results in the release of energy which the organism needs and without which it would not be able to undertake any of its activities.

This oxidization takes place in different ways in different animals, but in all cases the result is the same: the release of energy. At the same time, water and carbon dioxide are formed as a result of this process. So the main stages of breathing are the intake of oxygen needed to oxidize the nutrients and the release of carbon dioxide and water as a result of this process.

In simple animals like the amoeba, where the body consists of a single cell, the process of breathing is completed in a very simple manner. The creature that looks like a piece of soft jelly, lives in water. There is a certain amount of diluted oxygen. This oxygen which is diluted in the water penetrates the amoeba's body, where it oxidizes the nutrients in its body, and the energy is released which it needs to move and grow and perform other necessary functions of life.

Carbon dioxide and water are formed as a result of this oxidization process, in addition to the release of energy.

The amoeba gets rid of the excess water in an amazing fashion. It collects the drops of water until they form a bubble filled with water. It then moves to the edge of the creature's body. Then it bursts, expelling the water from its body, then it starts to form a new bubble, and so on.

The carbon dioxide simply passes out from the amoeba's body into the surrounding water.

In insects, the function of breathing takes place through openings in the sides of the insect's body which lead to a network of fine tubes and get progressively smaller until they reach almost all its cells. Oxygen enters this system through the external holes, and reaches the cells of the body directly.

In man and a number of other animals, the oxygen reaches the tissues of the body through red blood cells which are carried by the blood and which contain a substance called haemoglobin.

One of the amazing features of this substance is that it binds readily with oxygen and carbon dioxide, and is also able to detach itself quickly from them. When these red blood cells reach the lungs, they pick up oxygen and travel through the arteries until they reach the small capillaries in the tissues of the body, where they release the oxygen. The oxygen passes through the thin walls of the capillaries into the tissues, where it is used to oxidize the nutrients. The carbon dioxide which results from this process of oxidization attaches itself to the haemoglobin and is carried back to the lungs, where it detaches itself and is expelled from the body by exhalation. Then more oxygen is picked up, and so on.

Breathing happens in different ways in different animals, but the result in all cases is the same, that is, bringing oxygen to the cells of the body and expelling carbon dioxide.

First, the precise nature of this process has to be the action and decree of a Creator, because it could not have happened any other way. This result which all creatures have in common could not have come about by accident.

Second, the Creator is absolutely One, for the style of creation is based on one principle and leads to one unchanging result."

On this topic, Dr. Yusuf tells us:

"All living beings, plants and animals, need nourishment. The way in which plants get their food is completely different from the way in which animals get theirs. Plants stay in one place and are not able to move around to look for their food as animals do so. Hence they manufacture their own food on the spot, by using solar energy.

Animals, on the other hand, find their food ready-made, whether it is plant material or from other animals. The food which animals eat has to be digested and absorbed by the body so that it can benefit from it. The process of digestion is very complicated, as it breaks down complex substances into simple substances which the body is then able to absorb and benefit from.

The food substances may be fats, proteins, starches, etc. Each type of food is digested by specific enzymes which affect it but do not affect other substances which may be present side by side with it. Enzymes which work on fats will not work on proteins, and enzymes which work on proteins will not work on fats.

Is it possible that all of this could have come about as the result of blind chance or accidents, or as the result of trial and error?

Any mind which is able to think must realize that this is impossible, just as this idea is rejected outright by the mathematical laws of probability.

The minute amoeba, which is formed of a single cell, takes in its food in a strange manner. It extends a pseudopodium which surrounds the piece of food which is to be found in the water surrounding it. The food may be either tiny animal organisms or single-celled plants which are smaller than the amoeba. In this case the food will be moving if it is a tiny animal organism, and stationary if it is a single- celled plant, such as some water mosses.

It is indeed remarkable that a simple creature such as the amoeba, which has no brain or nervous system, is able to distinguish between food that is stationary and food that is moving. If the food is a moving animal, the amoeba approaches it with caution from a distance so that it will not run away. If the food is stationary and is not moving, the amoeba approaches it without caution, touching it as it surrounds it, because in this case the food is not able to escape. How does a simple creature like the amoeba, which we can barely see without the aid of a microscope, and which has no brain, nerves, eyes or other sensory organs, know this?

Once the food has been surrounded by the pseudopodium, it is now inside the amoeba's body, encased in a drop of water. Then the amoeba's body begins to secrete an acidic digestive enzyme which kills the prey which it has caught, if it is still alive. Then it secretes an alkaline enzyme. There is a reason for this, the most important enzyme, which is the one which digests proteins, can only work in an alkaline environment."

"Blood circulation takes place in different ways in different parts of the animals' bodies, just as the formation of the heart varies in different kinds of animals, but the result is the same, blood circulation in parts of the body.

If we look at how the heart and circulatory system is formed in man and in a number of other animals, we will see that the heart — this beautifully designed organ- is formed of interconnected chambers whose openings are equipped with valves. The job of these valves is to allow blood to pass through in one direction, and to prevent it going back in the opposite direction.

We find similar valves in the large veins for the same reason.

The network of blood vessels, with its arteries, veins and capillaries, is designed in an amazing manner. The arteries branch out, getting smaller and smaller, until they become capillaries with thin walls.

The reason why the capillaries have such thin walls is to allow the gaseous exchange of oxygen from the haemoglobin carried in the red blood cells to the tissues of the body. At the same time, carbon dioxide passes from the tissues into the capillaries, where it attaches itself to the red blood cells. Then the capillaries join back together to form veins which lead back to the lungs, where the red blood cells get rid of the carbon dioxide and pick up more oxygen, and so on.

The heart beats rhythmically for a lifetime, whereby some of its chambers expand whilst others contract, to push the pure, oxygen- bearing blood through the arteries, whilst the blood that has passed through the body returns carrying carbon dioxide, to send it to the lungs where it picks up more oxygen and gets rid of the carbon dioxide.

There circulate in the bodies of man and some other animals fluids which have specific functions, such as blood and lymph. The lymph acts as a mediator between the blood and the tissues. Blood has many functions, such as delivering nutrients to all parts of the body. If blood does not exist in the bodies of some animals, such as the liver- worm, the bodies of these animals are designed in such a way that nutrients are delivered by some other means.

In our bodies and in the bodies of a number of other animals, blood is composed of a liquid in which there float huge numbers of cells which have different forms and functions. These are called red blood cells and white blood cells.

The red blood cells, as mentioned above, play a role in the function of breathing. The white blood cells appear in a variety of forms and perform different functions. Some of them serve to swallow and destroy any germs that enter the human's or animal's body; they swallow them in a manner similar to that of the amoeba swallowing its food. We breathe in from the air millions of germs day and night, but we do not get sick every day, because these amazing cells which float in our blood and which are able to move from the bloodstream into the tissues in cases of emergency, swallow these germs and kill them. So we do not fall ill unless the body's resistance is weakened for some reason, or if there are more germs than usual.”