How are DNA, genes, chromosomes related?

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
student12
Death Adder
Death Adder
Posts: 57
Joined: Wed May 10, 2006 10:36 am

How are DNA, genes, chromosomes related?

Post by student12 » Sun May 14, 2006 12:42 pm

What I do know is that genes are on chromosomes and that DNA are the genetic material of an organism. DNA is a long double-stranded helix, but there are many chromosomes.
Basically how are chromosomes and DNA related and differ from each other?
because that is the only reason why they are named differently.

User avatar
victor
King Cobra
King Cobra
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..
Contact:

Post by victor » Sun May 14, 2006 12:47 pm

Chromatid is a densed, coiled DNA + histones.
2 chromatids = 1 chromosome (with a few wxceptions)
Q: Why are chemists great for solving problems?
A: They have all the solutions.

User avatar
LilKim
Coral
Coral
Posts: 436
Joined: Mon Mar 20, 2006 8:36 pm
Contact:

Post by LilKim » Sun May 14, 2006 10:35 pm

Chromosomes are primarily composed of DNA... Basically what happens is that... DNA wraps itself around chromosomal proteins into structures called chromosomes..

Genes are units of DNA that have a specific function... genes are composed of DNA and reside at different location along chromosomes...

hope this helps!
- KIM

student12
Death Adder
Death Adder
Posts: 57
Joined: Wed May 10, 2006 10:36 am

Post by student12 » Tue May 16, 2006 11:22 am

Thx alot guys that really helped, especailly KIM

User avatar
LilKim
Coral
Coral
Posts: 436
Joined: Mon Mar 20, 2006 8:36 pm
Contact:

Post by LilKim » Tue May 16, 2006 12:55 pm

no problemmo... good luck with your studies!

- kim

spark13579
Garter
Garter
Posts: 10
Joined: Mon Feb 27, 2006 2:26 am

Post by spark13579 » Sun May 28, 2006 5:08 am

This always confused me. We are led to believe that human beings have 23 pairs of homologous chromosomes, and that each pair contains two "different versions of the same gene", called alleles.

However, during the transcription stage of protein synthesis the DNA double helix unwinds and DNA polymerase enzyme synthesises a complimentary primary mRNA chain of nitrogenous bases. What I don't understand is how this ties in with the gene/2 versions/allele terms that we read when studying mendelian genetics.

Which gene version is read by DNA polymerase? And what happens to the other version of the same gene on the other homologous chromosome? And what happens to so called recessive genes? Are they never switched on? (ie. transcribed and translated into protein chains).

This is quite possibly the most confusing problem in biology for me. I don't understand why it isn't written clearly in any book I read. People are either talking about mendelian genetics and using terms like chromosome, allele, dominent and recessive, or else they are talking about the stages in protein synthesis and using terms like polymerase, gene (but with apparently a slightly different meaning) and the coding of amino acid structure. The two are rarely, if ever, interchanged.

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 9 guests