Explain "Crossing-over", What is it? When does it occur? Why is it important?
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It happens during meiosis, when the gametes are being formed. You know how chromosomes, in diploids, divide so that half of them go into one of the eggs/sperm and the other half go into the other, so that there's one of each in the gamete?\n\nWell, that is a way to re-combine the genetic material so that the offspring will have some from mom and some from dad. It's like having two sets of encyclopaediae, and combining them so that two new sets are produced, each with books from the two parents.\n\nNow imagine you have Volume 21 of the encyclopaedia from mom, and Vol. 21 from dad. You could assign one or the other to the new set being formed, but you want even more variety in the information.\n\nSo you take pages from one Volume 21 and _switch_ them with the equivalent pages from the other Volume 21.\n\nThat is crossing over and recombination. It increases the amount of possible children generated enormously.\n\nIt happens just before the chromosomes are segregated. In humans, we have 23 pairs of chromosomes. During meiosis, those 23 pairs split, forming 2 sets of 23 pairs each (chromatids). Those sets separate, and within each set the pairs recombine--that is, they cross over each other and exchange segments. Just like switching equivalent pages between the two same-numbered volumes of an encyclopaedia set.\n\nThat way the two sets of pairs, who will go on to form four new gametes, contain chromosomes that are neither identical to mom's nor to dad's, but a combination of segments of the chromosomes from both.
374170
Cross-dressing is the act of wearing clothing commonly associated with another gender within a particular society.\nSuch as a man dressing as a woman or a woman dressing as a man.
1169109
Crossing over increases genetic diversity.
801991
Independent Assortment:\nThe chromosomes of each parent sort independently in the production of gametes, so any combination of the chromosomes is possible in the offspring.\n\nCrossing Over:\nThe swapping of segments of a chromosomes between each other.  Crossing Over creates novel combinations of alleles for various gene loci.  These combination of alleles were not present in either parent.
245230
Walking the line between genius and insanity, or sanity and insanity.  There is a point at which you cross to the other side.
489957
Yes, that's happened in my life lots of times. Way cool, isn't it? Enjoy it man. Its a real joy and blessing. ;-)
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#1)  Primarily by mutation.  A mutation must occur a germ cell (cells that produce sperm and eggs).  This can produce progeny with novel traits.  This is fairly rare event (one out of every billion nucleotides copied during meiosis).  Our body has ways of fixing these errors, but this is the biological basis of evolution.\n#2)  By crossing over.  During meiosis, parental chromosomes will swap pieces with each other.  For example, I used pieces of my mother's chromosome #1 and my father's chromosome #1 when I made the chromosome #1 that I passed to my daughter.  I passed a different combination of pieces to construct a chromosome #1 for my second daughter.\n#3)  By independent assortment during meiosis.  So not only did I make novel chromosomes out of pieces of my parents chromosomes, but I created a gamete using a unique combination of my mother and father's chromosomes.  For example I might have used chromosomes 1-11 of my father's (with pieces of my mother's chromosomes 1-11) and numbers 12-22 of my mother's (with pieces of my father's chromosomes 12-22).  For my second daughter it could have been totally different.  It is a unique situation each time!  No two gametes are the same.
128581
I'm pretty sure that its random because in meiosis there is crossing over. The chiasmata are where the chromosomes cross, which is done randomly. Since the codons are part of the DNA, they would be crossing at random too. The only exception that I can think of is when genes are located at least within 50 map units of eachother on the chromosomes, which makes it more likely that the genes will cross over together.\nHope this helps!
185726
If you mean what I think you mean, "crossing over" is that process of death, and the journey to reaching the other side. The other side could be someday sharing eternity with our Creator! \nIs this the "crossing over" that you are talking about?
921029
It's called Parkour from the French for crossing 'parcours', as it originated from street kids jumping across from building to building.  Check out the website www.parkour.com
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A cross-clamp is a tool used to close off (clamp) a large artery, often the aorta, during surgery when it is necessary to prevent blood from passing through that vessel. This is what cross-clamp means. Think of it as a large hemastat, it stops blood.\n\nHow is it done? Suppose you have damage to a large artery. I could cross-clamp the artery above the damage, temporarily stopping blood from flowing through the damaged area while I make the repair.  When I'm confident the repair will hold, I release the clamp and watch for leaks.  \n\nHow does it apply to heart surgery?  If repair needs to be done to the heart, it's much, much easier to do this and see what you're doing if the heart isn't full of blood.  But you gotta work FAST.
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http://www.rc.net/wcc/cross.htm
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I think it originates from having used a finger from each hand to form an actual Cross. over time it became more practical to use two adjoining fingers on the same hand(the non dominant one) as it allowed the free hand to work on the task at hand
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WOW! Why don't you cross in the opposite direction and stay.
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Of course.  Those that haven't yet gone to the Other Side sometimes are waiting around for differnt reasons.  Unlike people assume, they are typically not mad or trying to tell us anything.  They are only confused.  They wonder on a different "plane" kind of.  White noise is kind of like when ours crosess with theirs for a few seconds, maybe even minutes at a time.  There are many other ways to communicate with them though.  Those who have already crossed over, are always around telling us things...leaving coins or other items lying around, using our phones, computers, radios, lights, or any other electronic devices.  Open yourself up and you'll learn a lot from them.
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I have found that some sects in Christianity have no problem with this type of ceremony.  I know that as my husband and I got married (he's catholic and I was raised jewish) that the Catholic Church would have no problem with us getting married and would request a neutral location and that clergy from both religions be allowed to preside. I think the 2 faiths are used to crossing over in some cases.
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It doesnot matter whether the player is on right side or the left...If he crosses before the opponent team then he is given offside..on side is when the player is taking corner....