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Hi!
I have a few questions about some gene information: 1) there are 46 chromosomes in the human cell, so are there 96 chromatids? 2) There are 23 chromosome pairs, so are the 2 chromosomes in each pair identical, i.e.- do they have the same genes in the same loci? i.e.- if you look at one in the pair, is it equivalent to looking at the other one? 3) how can you find out how many genes are on 1 chromosome?
Thank you so much!!
juggernaut
Chromosomes
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D. Park
- Former Expert
- Posts: 6
- Joined: Sat Sep 23, 2006 9:40 pm
Hey juggernaut...
You can do a simple google search for chromosomes to find the answer to these questions.
Here's the Wikipedia explanation of chromosomes: http://en.wikipedia.org/wiki/Chromosome
D. Park
You can do a simple google search for chromosomes to find the answer to these questions.
Here's the Wikipedia explanation of chromosomes: http://en.wikipedia.org/wiki/Chromosome
D. Park-
carolinethorn
- Former Expert
- Posts: 393
- Joined: Tue Sep 20, 2005 2:40 pm
Hi Juggernaut,
Remember from sexual reproduction, that when a human starts out it gets half its DNA from the chromosomes in the sperm from the Dad and half from the egg from the Mom. So chromosomes are not identical. The organization of the genes on the chromosomes is the same but there are very small differences between the chromosomes from the Dad and from the Mom, they are less than 1% different. If you looked at the chromosomes under the microscope they would look identical because the differences are so small - you would need to look at the individual DNA sequences to see the differences.
Do you know about the human genome project? This was a giant experiment carried out by scientists from lots of differnt countries to find out the average DNA sequence of all of the human chromosomes that make up the genome. (There is also a project called the HapMap which was to try and find out all of the places in the DNA sequence where it can be different between different people). You can look at the results fo the human genome project at this website :
http://www.ncbi.nlm.nih.gov/mapview/map ... taxid=9606
This will let you lclick on chromosome 1 and see all of the genes that are located there and you can even see what the DNA sequence is for each of them.
Best of luck,
Caroline
Remember from sexual reproduction, that when a human starts out it gets half its DNA from the chromosomes in the sperm from the Dad and half from the egg from the Mom. So chromosomes are not identical. The organization of the genes on the chromosomes is the same but there are very small differences between the chromosomes from the Dad and from the Mom, they are less than 1% different. If you looked at the chromosomes under the microscope they would look identical because the differences are so small - you would need to look at the individual DNA sequences to see the differences.
Do you know about the human genome project? This was a giant experiment carried out by scientists from lots of differnt countries to find out the average DNA sequence of all of the human chromosomes that make up the genome. (There is also a project called the HapMap which was to try and find out all of the places in the DNA sequence where it can be different between different people). You can look at the results fo the human genome project at this website :
http://www.ncbi.nlm.nih.gov/mapview/map ... taxid=9606
This will let you lclick on chromosome 1 and see all of the genes that are located there and you can even see what the DNA sequence is for each of them.
Best of luck,
Caroline
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juggernaut4
- Posts: 128
- Joined: Sun Jun 04, 2006 12:21 pm
Hi, Caroline.
Thank you for the reply. I had found the link earlier, but I asked the loci question because the link only gives you 22 chromosomes (plus sex chromosomes). Why don't they give you all 46 if all chromosomes have different genes? And what is the MT chromosome for? Also, is there software that helps you find the intergenic regions in a length of DNA?
Last question.. how do you find the actually nucleotide sequence from the link you gave me? Thank you again!
juggernaut
Thank you for the reply. I had found the link earlier, but I asked the loci question because the link only gives you 22 chromosomes (plus sex chromosomes). Why don't they give you all 46 if all chromosomes have different genes? And what is the MT chromosome for? Also, is there software that helps you find the intergenic regions in a length of DNA?
Last question.. how do you find the actually nucleotide sequence from the link you gave me? Thank you again!
juggernaut
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carolinethorn
- Former Expert
- Posts: 393
- Joined: Tue Sep 20, 2005 2:40 pm
Hi Juggernaut,
Sorry if I was confusing before. And if I use any jargon you don't understand please prod me and I will explain - I don't know how much you know yet about the basics of DNA.
What I was trying to say was that each copy of chromosome 1 has the same genes in the same order but they are not quite identical. Identical would have to be 100% the same and they are more than 99% the same but not identical but to show all of the possibel versions would take up too much space so what they show at the NCBI is the "consensus" human genome sequence which is basically the average. So that is why they have 22 plus X and Y.
The MT chromosome is the mitochondrial DNA. This is a chromosome inside the mitochondria not inside the nucleus with all the other chromosomes but it still has genes that makes proteins on it so its included in the genome. The MT chromosome comes only from the mother as it is present inside the egg when fertilization ooccurs. The sperms mitochondria are left outside with the body of the sperm and only the nuclear material goes into the egg to become part of the embryo.
I know there is software that helps you to find genes (or potential genes called ORFs or open reading frames). It is called ORF finder and is available at NCBI. I am sure there are lots of others you can find by googling "ORF" and "find" or "search". You could find the intergenic regions by subtracting the genes from the DNA.
To find actual nucleotide sequences you just have to keep clickign and zooming. If you want a specific gene sequence you can search for it by gene name also. Another place that is good to get sequence from is UCSC Golden Path - this is another type of browser to view the human genome project data. I find it easier to get big sections of sequence there because you can search by the base numbers.
Let me know if you need help with finding specific sequences. If you explain what you are trying to do also then people may have more advice.
Best of luck,
Caroline
Sorry if I was confusing before. And if I use any jargon you don't understand please prod me and I will explain - I don't know how much you know yet about the basics of DNA.
What I was trying to say was that each copy of chromosome 1 has the same genes in the same order but they are not quite identical. Identical would have to be 100% the same and they are more than 99% the same but not identical but to show all of the possibel versions would take up too much space so what they show at the NCBI is the "consensus" human genome sequence which is basically the average. So that is why they have 22 plus X and Y.
The MT chromosome is the mitochondrial DNA. This is a chromosome inside the mitochondria not inside the nucleus with all the other chromosomes but it still has genes that makes proteins on it so its included in the genome. The MT chromosome comes only from the mother as it is present inside the egg when fertilization ooccurs. The sperms mitochondria are left outside with the body of the sperm and only the nuclear material goes into the egg to become part of the embryo.
I know there is software that helps you to find genes (or potential genes called ORFs or open reading frames). It is called ORF finder and is available at NCBI. I am sure there are lots of others you can find by googling "ORF" and "find" or "search". You could find the intergenic regions by subtracting the genes from the DNA.
To find actual nucleotide sequences you just have to keep clickign and zooming. If you want a specific gene sequence you can search for it by gene name also. Another place that is good to get sequence from is UCSC Golden Path - this is another type of browser to view the human genome project data. I find it easier to get big sections of sequence there because you can search by the base numbers.
Let me know if you need help with finding specific sequences. If you explain what you are trying to do also then people may have more advice.
Best of luck,
Caroline
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juggernaut4
- Posts: 128
- Joined: Sun Jun 04, 2006 12:21 pm
Hi, Caroline.
Well, I've seen a few people asking around this forum for a mentor. In your occupation section, it says you have a job dealing with genetics. Would you be able to help me with a genome project? If you need more information, please let me know! Thank you so much (also for the information; for the intergenic genes, I tried the INCLUSive intergenic software, but I couldn't get it to work.. maybe if I could email you, you could tell me software jargon? thanks!)
juggernaut
Well, I've seen a few people asking around this forum for a mentor. In your occupation section, it says you have a job dealing with genetics. Would you be able to help me with a genome project? If you need more information, please let me know! Thank you so much (also for the information; for the intergenic genes, I tried the INCLUSive intergenic software, but I couldn't get it to work.. maybe if I could email you, you could tell me software jargon? thanks!)
juggernaut
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carolinethorn
- Former Expert
- Posts: 393
- Joined: Tue Sep 20, 2005 2:40 pm
Hi Juggeranut,
Glad to be of help. I used to work for the Pharmacogenetics and Pharmacogenomics Knowledge Base - a database about genes and drugs, so yes this is in my area of expertise.
I am not mentoring any other students at the moment and would be happy to act as a mentor for you for your genomics project. I will ask the Science Buddies administration about how to set it up.
-Caroline
Glad to be of help. I used to work for the Pharmacogenetics and Pharmacogenomics Knowledge Base - a database about genes and drugs, so yes this is in my area of expertise.
I am not mentoring any other students at the moment and would be happy to act as a mentor for you for your genomics project. I will ask the Science Buddies administration about how to set it up.
-Caroline
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carolinethorn
- Former Expert
- Posts: 393
- Joined: Tue Sep 20, 2005 2:40 pm
Hi juggernaut,
I sent an email to inquire how its going. You could also ask your parent or guardian to contact science buddies by email as they will need to give permisssion
(see https://www.sciencebuddies.org/mentorin ... ctus.shtml for the details)
I understand you want to get going on your project but try to be patient as most people involved are volunteers and have other jobs as well.
-Caroline
I sent an email to inquire how its going. You could also ask your parent or guardian to contact science buddies by email as they will need to give permisssion
(see https://www.sciencebuddies.org/mentorin ... ctus.shtml for the details)
I understand you want to get going on your project but try to be patient as most people involved are volunteers and have other jobs as well.
-Caroline
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LisaBug
- Former Expert
- Posts: 26
- Joined: Mon Oct 16, 2006 1:11 pm
Re: Chromosomes
Juggernaut,
Check out Matt Ridley's book Genome, the autobiography of a species in 23 chapters.
Each chapter is devoted to a chromosome. He is a great writer, easy to understand, it will give you a good background and a basis on which to ask your questions.
LisaBug
Check out Matt Ridley's book Genome, the autobiography of a species in 23 chapters.
Each chapter is devoted to a chromosome. He is a great writer, easy to understand, it will give you a good background and a basis on which to ask your questions.
LisaBug
juggernaut4 wrote:Hi!
I have a few questions about some gene information: 1) there are 46 chromosomes in the human cell, so are there 96 chromatids? 2) There are 23 chromosome pairs, so are the 2 chromosomes in each pair identical, i.e.- do they have the same genes in the same loci? i.e.- if you look at one in the pair, is it equivalent to looking at the other one? 3) how can you find out how many genes are on 1 chromosome?
Thank you so much!!
juggernaut