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November 2, 2006 at 4:20 pm |
Warum mein Fikus hat weisse Streifen am Rande von Blaettern? Und anderer hat nur gruene Blaetter? (Du darfst in Englisch antworten, ich dagegen kann noch nicht in Englisch gut schreiben:)
November 2, 2006 at 4:51 pm |
Dear Stasia, I am sure you wanted to ask this question in the Biology Forum. I reply you here because it’s easier. A leaf is made of 3 distinct cell layers. Those 3 layers make the leaf as two peaces of bred and one slice of salami make a sandwich. At its borders, the leaf is made only of the two external layers, like in the sandwich, when you give the first bite, you’ve only bread because the salami has a smaller diameter. In most of the plants, the 3 cell layers produce chlorophyll. Then, the whole leaf is green. In your mutant ficus, only the “salami layer” (the inner one) makes chlorophyll. So, the borders of its leaves are white.
November 7, 2006 at 12:42 am |
What do you think about MAS?
Links to Report: 05/11/2006:
http://www.media.rai.it/mpmedia/0,,report^13151,00.html
http://www.report.rai.it/R2_popup_articolofoglia/0,7246,243%255E1068990,00.html
November 7, 2006 at 10:46 am |
The Marked-assisted selection is not a new technology. MAS can be applied to plants as well to animals: individuals of the same specie are crossed and the progeny with the desired qualities is selected. This is what farmers did for thousands years. MAS speeds up the selection time, as you “see” in the genome of the progenies the quality you need without waiting for the individual to grow until maturation (until fruit production, for example). BUT, in theory it is a really helpful technique, in practice there are several problems. We don’t know yet which gene is responsible, for example, to produce juicy meat instead of tasteless. And, in 99.9% of the cases, one gene is not the only responsible of a special trait. Then, you have to select for multiple markers to obtain the product you desire, and after crossing it is not easy to find individuals carrying all the markers responsible of your trait of interest. Of course, this method is not invasive at all, in comparison to GMO. But what are the real potentialities of MAS is not yet clear, as our knowledge is not enough developed.
February 6, 2007 at 12:02 am |
why bold people are pretty and more clever than other people?
February 6, 2007 at 12:42 am |
Our dearest reader, we reply to you with pleasure. Your observation is due to the partly wrong assumption that bold equals to high levels of male hormones. A recent study published on Science showed that high levels of male hormones make people fat and clever, while high level of female (!!) hormones make people thin and bold. As the world community is rapidly changing sex behaviors and tastes, nowadays male with high female hormone levels are considered beautiful. The same effect is described by the Ancient Greek philosopher Plato. We hope we replied to your answer. Best regards, Lorana Staff.
March 6, 2007 at 1:06 pm |
Take a look at this:
http://www.hwupgrade.it/news/storage/il-futuro-dello-storage-nei-batteri_20356.html
What’s your opinion?
March 20, 2007 at 8:20 pm |
La cosa non e’ stabile come viene mostrata. Ricombinazioni e mutazioni avvengono sovente nel genoma. I virus ricombinano molto facilmente: ogni anno un ceppo differente per l’ influenza. I batteri pure, anche se non saprei riportarti dati sulle percentuali. Quindi, immagazzinare un’ informazione in un batterio non mi sembra un’idea eccellente. Una volta integrata nel genoma, potrebbe essere mutata o scartata se nociva. Questa notizia mi ricorda le piante transgeniche per identificare le mine antiuomo. Le piante crescerebbero rosse se a contatto con polvere da sparo. In laboratorio per una generazione di piante puo’ anche funzionare, ma sovente le progenie successive non mantengono la stesse efficienza per i transgeni che sono stati inseriti. E perdere una gamba perche’ una stupida pianta non diventa piu’ rossa mi sembra troppo. Ricordiamo che “evoluzione” significa “mutazione” nel DNA. Quindi pensare che in 100 milioni di anni un ceppo batterico conservera’ il suo genoma come oggi, mi sembra un grande bufala!