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The Plant Stem: A Matchless Transport System From the smallest grass-like plant to the largest tree in the world, every plant has to distribute the water and minerals which it takes up through its roots to all of its parts, including the tips of its leaves. This is a very important function for plants, because water and minerals are what the plant needs most.
In all their activities, photosynthesis included, plants always need water, because many essential processes in plants are ensured just by using water. These include:
- the maintaining of vitality and tension of cells,
- photosynthesis,
- the absorption of food substances which have dissolved in the soil,
- the transport of these foods to different parts within the plant body,
- producing the cooling effect on the surface of leaves in hot climates, thus protecting them from harm.
But how are water and mineral salts taken up by the plants from where they are hidden deep in the soil? Furthermore, how do plants disperse these substances, which they have taken up through their roots, i.e. send them to different regions of their bodies? What methods do they use while carrying out these difficult processes?
When answering these questions, the most important point, and one which must not be forgotten, is that it is quite a difficult job to raise water up to heights of hundreds of metres. In our day these processes are implemented by means of various pressure tank systems. The transport systems in plants also use this kind of system.
The existence of this water tank system in plants was discovered some 200 years ago. But no scientific law has yet been established to definitively explain this system, which permits the drawing up of water in plants against the force of gravity. Scientists just propose a number of theories on the subject and count the most likely and satisfying of these theories as valid.
All plants are provided with a distribution network so that they can draw up the materials they need from the soil. This network sends these substances and water acquired from the soil to where they are needed, in the appropriate quantities, and in the shortest possible time.
According to scientists' discoveries, plants use more than one method to manage this difficult task.
The transport of water and nutriments takes place inside plants thanks to structures with completely different features. These structures are the specially planned transport tubes.
Water Transport
- No matter what the size of the plant in which the transportation process is to take place, the tubes which make up the transportation system are about 0.25 mm (in oak) to 0.006 mm (in linden) wide, some being made up of dead plant cells, others of living plant cells 50 and are woody tissues with no other features than what we have described. These structures have the ideal design necessary to transport the water plants need to a height of hundreds of metres.
This transport system starts to work with the leaves losing water. The transport system in plants is set in motion with processes which take place in the stomata (pores) normally on the undersides of leaves, but in some species, on the top.
If the external humidity level is less than 100%, evaporation occurs in the leaf and water is given off by the stomata. Even if the humidity is 99%, this still means a potential situation for the water in the leaves to be exuded, and the leaves rapidly begin to lose water. In this way, plants need to make good the loss of water that comes about with the evaporation through the leaves of the water taken from the soil.
As we have seen, the mechanisms in leaves are sensitive enough to identify a difference of just 1% in the humidity level. This is a very important property. When the other things going on in leaves are examined, it will be concluded these are processes whose secrets have not been fully mastered, even with the technology of our day. The miraculous processes going on in such a tiny area bring many questions to mind.
How did mechanisms which can initiate the necessary processes by detecting just a 1% drop in humidity come into existence in plants? Who is the author of the design of these mechanisms? How did such a technology, which has been working faultlessly for millions of years right down to the present day, come about?
It was not plants themselves which designed and implemented these mechanisms. Neither is it possible for an intervention by any other living thing to have installed such a structure in the leaf. It is beyond doubt that there is a superior intelligence which gave plants all the properties they possess, and installed these systems in areas just one hundredth, or even a thousandth of a millimetre across. The possessor of this intelligence is God, the Ruler of all the worlds, who keeps everything under control.
How Is Water Transported from the Soil to a Height of Hundreds of Meters?
The cell cavity is connected to with the interior cavities of neighbouring cell above, below and at either side. A strand of tracheids thus forms a series of pipes along the stem with constrictions at the holes in the walls where two cells make contact. These constructions increase the resistance of the pipe to the flow of water.
All the features we have counted so far are the first step in the foundation necessary for water to be transported in plants in a secure manner. The pipes formed by these cells must be able to withstand the pressure that is formed when the water is sucked up. As we saw above, this is brought about by means of the holes between the cells. Then it has to be ensured that there is no obstruction when the materials are being transported, because any obstacle in the route they traverse will result in a chain reaction of faults in the whole system. This possibility is prevented by the death of the cells and the formation of the empty tubes. The cell walls of the xylem tubes are quite thick, because water will travel up these as it is sucked up under a certain pressure. The tubes have to be able to resist this quite strong negative pressure. A kind of water column forms in the tubes. The tensile strength of this column must be strong enough to carry water to the furthest point of the tallest known tree in order for the plant to survive. Thanks to this strength, water can rise up to 120 metres, as in the mammoth tree.52
The coming of the water from the soil to the xylem tubes happens by means of the roots. At this point the importance of the root's internal layer emerges. There are protoplasms in the root cells. These protoplasms are structures made up of water for the most part, and for the rest of carbon, hydrogen, oxygen, nitrogen, sulphur, sometimes proteins containing phosphorus, carbohydrates such as starch and sugar, oils, and various salts. And they are surrounded by a semi-permeable membrane. This allows certain ions and compounds to pass through them easily. This special structure of the root allows water to be taken up easily.53
Food Transport
The phloem tubes through which nutriments are carried by are made up of two different kinds of cells. These are the sieve cells, through which the nutrients are transported, and the companion cells. Both these cells are elongated, and completely different in structure to the cells in the xylem tubes. This difference can be clearly appreciated when their structure is examined. Both the cells in the phloem system have extremely thin walls. They are also living cells. Those in the xylem tubes are dead.
Research into the sieve cells which make up the phloem tubes has revealed that they lack a nucleus. This is most interesting, because the cell nucleus is where all the information required to keep the cell functioning is hidden. The sieve cell lack a nucleus, because such a bulky object in each cell would impede the flow of the nutrient solution. This is where the companion cell comes in: the companion cells contain very dense cytoplasms and a prominent nuclei and they are, in fact, sister cells to the sieve cells with which they are associated.
There is a quite detailed planning in plants' transport systems. And the function, and hence structure, of every cell is different. In the face of these details, the question comes to mind of how they could have been placed in such a small area.
It is impossible for such a system to have come about by chance. This system is the result of specially prepared planning. Let us examine how such a complex and unique system could not have come about by chance by asking some questions.
With what timing or method could the development we have been discussing, in other words, the cell's nucleus being absent only in this type of cell have come about? How could coincidences have decided to dispense with the nuclei only of certain cells? Let us assume that they did so decide: in such a situation, could the structure in question have come about by waiting for coincidences over thousands or millions of years? This question must definitely be answered. It is certainly not possible. If we think, we can see this. What would happen if the cells in a plant's phloem tubes did have nuclei? In this case the plant would die the first time an obstruction arose. That would mean the plant's disappearance, and for that reason the disappearance of the whole species shortly there after. If we consider this system, which is present in all the plants in the world, it will be even clearer that the transport mechanisms in plants could not have come about by chance. As we have seen, these tubes have to have possessed all their features in their entirety from the moment they came to be right down to the present. There is no question of plants' developing over time.
Moreover, it will not be sufficient for the equilibrium in such a complex and flawless system to have been brought about once. Because in plants, the xylem tubes and phloem tubes develop afresh every year. The system, all its structures, the features peculiar to it, the particular cell structures, the speed of functioning of the system and other details are renewed every year, with nothing going wrong.
Furthermore, as opposed to the transport of water, the cells used in the transport of nutrients are living. What is the reason for this difference?
This difference between the two systems which are present in the body of the plant is most important, because in order for the minerals to be able to move forward in the food transport system, the cells operate directly, for which reason they have to be living. But the cells in the xylem system just function as pipes for the transport of water, and what conducts water to the leaves is the internal pressure. This is the reason why a system consisting of living cells was set up for the transport of nutrients.
In this paragraph let us consider those sentences in a little more detail. The cells which make up the plant identify those regions where sugar is at low levels, and conduct it where they think necessary. If we think about it, it can clearly be seen that it is an extraordinary situation that cells should do such a thing. How does this come about? Is it possible for the cells to take such a decision on their own and establish the sugar levels? It is not possible, of course. Non-conscious cells cannot establish such a thing. They cannot know what other cells need. These cells in plants have submitted to God, like every other living thing in the universe, and operate in accordance with His inspiration. The Structure of the Stem
The job of distributing the minerals which the roots take from the soil falls to the stem. The stem distributes the minerals to the regions where they are needed in the most appropriate manner. For example, there has to be more calcium in the leaf stem, because the stem as the transporter of leaves and flowers needs a resistant structure. There is less calcium in the seed.
That faultless transport system in plants, whose plan has not yet been fully discovered, is the product of a totally conscious design. In other words, it is the work of a designer who possesses a most superior intelligence and superior knowledge. The designer is without doubt God, the Lord of all living things in the world, who knows what every one of their needs.
Dead Ends for Evolution with Reference to the Food Transport Systems
Evolutionists claim that all these systems in plants reached their perfect state as the result of uncontrolled coincidences over a period of millions of years. And according to evolutionists, for some reason nothing happened to plants while they were waiting for these processes to be completed. While every coincidence was taking place, the plant did not die because it was unable to produce food in the successive stages, it did not dry up from lack of water, but was able to survive all of these things for millions of years.
In this section only the structure of the transport system, of all the complex systems plants possess, was considered in broad outline. This subject is enough on its own to demonstrate the meaninglessness of the theory of evolution. Evolutionists' claims on this subject will be taken up in the section on the microbiological collapse of evolution.
All the features we have counted so far are just the general lines of the infrastructure necessary for the perfect functioning of the water and food transport systems. These complex mechanisms, whose general properties we examined without going into fine detail, are without doubt the work of a superior and matchless intelligence. For the transport of water there are canals made up of specially selected cells, and these have to be able to resist the pressure which results when water is being drawn up. This structure also has to lack protoplasms for the easy transference of the water. Food transport cells, on the other hand, have to be living, and also have to have a cytoplasm to transfer nutrients. So who brought about this water and food transport system, down to the finest detail, in plants? The plants? How can plants, which are made up of water-transport canals, leaves which carry out photosynthesis, branches, and outer coverings, establish the infrastructure for the transport process without knowing the physical properties of water, the pressure systems, and all the other details? Again, how can the food transport tubes find the best system for carrying sugar without knowing that substance's structure?
The number of such questions can be increased, but there is one answer to all of them. It is out of the question for plants to "establish," "design" or "find" such perfect systems. Plants possess no will. It is not plants which form these flawless systems which even scientists are hard pushed to "understand." Neither are they the result of coincidence.
It is God who installs all these systems in the required manner in the plant cells, and who creates the plants, the water, and the nutrients. Our Lord, who creates everything complete, reveals Himself in the most beautiful and the most perfect of creations.
50.
Prof. Dr. Ilhami Kiziroglu, Genel Biyoloji (General Biology), Desen
Yayinlari, December 1990, p.75 |
One
of the most widely accepted theories to explain how liquids are
sent from the soil to the leaves is the Theory of Cohesion. The
force of cohesion is a force produced by the tree's transport tubes,
known as xylem. This force increases the attraction between the
molecules which make up the water in the xylem. The xylem is made
up of two kinds of cells, called the tracheids and vessels, both
of which form pipes through which liquid can be moved. One of the
most interesting features of these structures is that once the individual
cells have reached their predetermined size and form, they promptly
die. There is a very important reason for this. During the transportation
of water in the tubes, it has to be able to move freely without
meeting any obstacles. In order to enable this to happen, a completely
empty tube must be formed. This is the reason for the protoplasm's
disappearance to leave the thick cellulose cell wall. The xylem
pipework in all living plants thus consists entirely of dead cells.
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