The multicellularity of our animals and the multicellularity of plants developed separately and each evolutionary branch found its own ways to stick cells together and sort them into specialized tissues, if there are unruly cells in one part of the plant they do not migrate to another place and therefore they are benign
The question in the title came up in the response For a column dealing with the extreme lifespan of trees. How is it that animals get cancer when genetic defects in the cells cause them to breed uncontrollably, while plants, which are also long-lived multicellular creatures, are exempt from this. This health is even more mysterious when you consider that plants, for photosynthesis, must have a large surface area exposed to sunlight.
In any multicellular creature, the cell should consider its neighbors to the tissue and not divide in a way that would damage the functioning of the entire organism. The same is true for plants as it is for animals or fungi. Every multicellular organism must develop mechanisms that prevent the uncontrolled growth of a single cell. but The multicellularity of our animals and the multicellularity of plants evolved separately and each evolutionary branch found its own ways to stick cells together and sort them into specialized tissues. Thus the proteins that glue our cells together is very different from the lignin polymer that serves this purpose in plants.
Plants have tumors but they do not metastasize
This is the place to be precise: although plants do not get cancer, they also develop tumors, that is, tissue that grows wildly at the expense of the neighbors. But in plants, these tumors are not malignant, meaning they do not metastasize: unruly cells from the root do not migrate to form secondary tumors in the stem or flowers. Unlike the animals, the plant has no equivalent to the blood or lymphatic system. Each cell is fixed to the place where it was created and can reproduce only at the expense of its nearest neighbors. In addition, the plant is a distributed creature, there is no plant equivalent to the heart, brain or liver: a vital organ located in a specific area and damage to which would be fatal. The vital activities: absorption of water and minerals, transport of materials, photosynthesis and reproduction are carried out by a multitude of root suckers, leaves, sap and saplings, branches and flowers. The meristem tissue made up of unsorted stem cells ensures that the plant can regenerate a damaged part. In the bosom of every leaf, say the textbooks for botany, is a bud. A small, modest bump that can develop into a new leaf, branch or flower. This decentralization allows the plant resistance and the ability to regenerate even from severe injuries and the loss of significant parts of the organism.
The most common plant growth - Etz
The most common among plant crops is the tumor: a growth that is sometimes caused by a local mutation, but is usually the result of the action of a parasite: an insect, worm, bacterium or virus. For example, wasps laying eggs in the branches of an oak tree cause a local growth that provides food and protection for the larva. These objects are rich in tannins: polymers with a high binding capacity to proteins. Similar tannins give the wine the ability to create the sensation of dryness in the mouth called, not coincidentally, astringency. The ancients already knew the sap of the oak and used the materials that can be extracted from them for leather processing and since the end of the Roman period also for the production of ink. According to the Shulchan Aruch, the Sefer Torah was written on leather ("parchment") processed with "Efzim water" with "settam ink" based on the gallic acid produced from apazim, i.e. from growths of the oak tree. This parasitic mechanism of causing a benign growth in a plant is so old that evolution has had time to create parasitoids, i.e. wasps that recognize the objects and turn the larva inside into food for their larvae.
Unlike human cancer, which is always harmful, there are plant tumors in which the invader that causes them benefits the plant. This is how the nitrogen from the air is fixed by bacteria that form tumors in the roots of legumes and the fig tree is fertilized by the wasp that forms excrement in it. The creator's ability to cause the plant's genes to create a structure suitable for its needs is still an enigma.
In her Nobel Prize acceptance speech she mentioned Barbara McClintock (Transposons: DNA segments that change their position in chromosomes) the objects as a still incomprehensible example of a "planned response" of the genome to an external disturbance. Thus, on the same vine, you can find 5 shoots of different structure and composition, each one is a growth left by another insect and adapted to its needs, and all of them are the results of different manipulations of the same genome. Aphid-forming bacteria insert a plasmid into the plant's genome that turns the cell into an uncontrolled growth center and causes it to produce nutrients for the bacteria. The mechanism by which other organisms cause plant tissue to become fibrous is not yet known.
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More of the topic in Hayadan:
6 תגובות
Why do dogs get colic? Because they are required to refrain from defecating. Unlike cats.
One should think about household services for a small dog and a large dog, in the meantime, as long as they "have to" eat
Meat and sell 230 kg of a 600 kg cow in the form of dry patties for pets.
By the way - in the XNUMXth desert and a traffic jam in the Suez Canal from election day for a week and animals for "fresh" meat
who were on ships. To mention a Hebrew date of a fire in the Notre Dame de Paris church.
To mention that the Passover sacrifice calls for release from slavery. Mention Miriam's date of death
Sister of Moshe and Aaron.
How do potatoes feel? Git Yen Derayit. And those who do know Yiddish will forgive me.
It should be noted the metabolic activity, animals consume oxygen and need antioxidants,
Excessive oxidation causes a chain of damages including malignant cancer.
which
You are basically giving the well-known theological argument that there must be a creator. You say "nature is complex so it cannot be created without a deliberate hand".
I will not enter into the discussion of whether the nature around us really cannot be created without a deliberate hand.
I just don't understand anything else, how is it that we can say that really by looking at the leaf of a tree we will come to the conclusion that it must have a planner. How is it that the next conclusion is that there is a God whom no one created? After all, God is more complex and wonderful than a tree, he is supposedly able to design a tree. The existence of God does not solve the question, on the contrary, it increases it.
How is it that your existence in the world does not seem logical to you that it was created by itself, but God does seem logical to you that it was created by itself?
If you can accept the existence of a wise, infinite, omnipotent God. that there is nothing that created him.
You must also be able to accept that the world may be that no one made.
It is sad to see people who feel that their faith is so threatened that they feel the need to belittle the science of genetics and the human knowledge that accumulates over the generations, to deny evolution instead of trying to understand it. Unfortunately, Judaism is in the dark days of stagnation and a mystical attitude that denies the reality that science reveals in order to preserve the faith as it understands it instead of understanding reality and thus getting closer to it. We are living in the middle ages of Judaism and I pray and hope that we will see progress towards the rational approach of Maimonides and that Judaism will break out of stagnation and continue to develop to the point where we do not see a contradiction between what we see and what we believe. Unfortunately, only virtuous individuals reach such a spiritual level and most of the people are in ignorance and observe mitzvot without understanding Judaism at all, as far as possible from the palace.
We should be happy about the progress of science, but at the same time, it is unfortunate to see such stupidity in people who are so out of their wits, the plant "found" a way to differentiate, even humans with the wisdom of genetics today and in a million years will reach such completeness, they did not find a way to differentiate, it happens in a deliberate way, on The hands of a householder with "a little" much more wisdom, these sophist fools
Thank you very much for the answer, I didn't think I would get an answer.
Really fascinating, I mean there are actually insects that carry out a kind of genetic engineering in plants?
It reminds me so much of Kohlat "What has been will be and what will be done will be done and there is nothing new under the sun." There is something that will say, look, this is new, it was already for the people who were before us"
Humans are just beginning to genetically manipulate other creatures for their needs, then discover that insects have been doing it for millions of years before them.