human embryo development

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weichungyi
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human embryo development

Post by weichungyi » Wed Nov 10, 2004 6:48 pm

One could argue that once a human egg is fertilized it is predestined to be a human according to human DNA. That would be one point of view.

I'm wondering if there is another valid point of view. Is there a point at which the embryo might reach some developmental stage that defines it as human versus maybe a stage where if other material is introduced it could develop into another species such as another primate?

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Post by intellectualfish » Fri Nov 12, 2004 2:22 am

The human zygote is always destined to be a human because it has the DNA of a human. There is no point during gestation where a zygote, embryo, fetus, etc. could magically turn into a different form of primate.

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biostudent84
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Post by biostudent84 » Fri Nov 12, 2004 2:55 am

Don't forget that other than size and genetic material, the human embryo is virtually identical to any other chordate. So is it truly human? One single chemical (DNA) inside a tiny nucleus is the only difference between a developing human and, say, a fish.

While this embryo will eventually become a human, in this stage an embryo is an embryo is an embryo.

(please rip this apart...I'll defend my statements when I'm not so wired from the caffeine and all-night studying :lol: )

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Post by Arsonus » Sun Nov 14, 2004 4:21 am

Ah, but one could say that only that one little chemical (DNA) is the difference between you and, say, a rock. Your DNA makes you human. You can't change that; you're always human. From conception on.

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Post by biostudent84 » Mon Nov 15, 2004 6:48 am

Agreed, DNA is what differentiates us from any other species (I think there might be a few more chemicals that differentiate us from rocks). But think of how similar DNA alone is to other creatures. Here is a list for comparison:

% DNA identical to Humans
Bacteria: 40%
Yeast: 60%
Dog: 90%
Monkey: 95%
Chimpanzee: 99.9%

There isn't that much difference in this little chemical to many creatures. Even more so when you consider that humans only use 10% of DNA (the rest has even been officially termed "Junk DNA.").

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Post by rjs07 » Fri Nov 10, 2006 4:58 am

You seem to be forgetting that each species has a unique chromosome number. Also the statement that there is one little chemical difference is false. There thousands of signaling molecules that are transcribed that direct our development as embryos. Many of these are the same, however many are not.

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sachin
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Post by sachin » Fri Nov 10, 2006 4:26 pm

biostudent84 wrote:Agreed, DNA is what differentiates us from any other species (I think there might be a few more chemicals that differentiate us from rocks). But think of how similar DNA alone is to other creatures. Here is a list for comparison:

% DNA identical to Humans
Bacteria: 40%
Yeast: 60%
Dog: 90%
Monkey: 95%
Chimpanzee: 99.9%

There isn't that much difference in this little chemical to many creatures. Even more so when you consider that humans only use 10% of DNA (the rest has even been officially termed "Junk DNA.").


It's right, But all embryonic developments are not only dependent of genetic constituations but also on Cytoplasmic inheritance.

Try this:
Insert human fertilised egg nuclii in monkey egg(on removing its nuclii). what will be the result?
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Post by druid » Sat Nov 11, 2006 12:54 pm

biostudent84 wrote:humans only use 10% of DNA (the rest has even been officially termed "Junk DNA.").


Incorrect.
Exons comprise 48 Mb of 3200 Mb of Human genome.
48/3200*100%=1.5%

Genomes 2, 3, T.A.Brown

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Post by druid » Sat Nov 11, 2006 1:35 pm

[email protected] wrote:Insert human fertilised egg nuclii in monkey egg(on removing its nuclii). what will be the result?[/b]


Do you know the answer?

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sachin
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Post by sachin » Sat Nov 11, 2006 3:47 pm

No haven't read about this experiment result, But surely heard that it has been carried out in US secreatly, result are secret too.

But experiments

http://www.csrees.usda.gov/nea/biotech/in_focus/biotechnology_if_animal.html

This will help for better understanding.
[url]
http://etd.lsu.edu/docs/available/etd-0 ... na_dis.pdf[/url]

This shows interspesies nuclear transfer is results in modified organism with combined, Nullified, or new characters that of Parental.
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Bitter Truth!
Who says reason for world war III will be Petrol?
Reason lies in two words "Me and Mine".

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