Roughly how many genes are there in a strand of DNA? Are we talking hundreds, millions, trillions?
2007-09-20 02:34:58 · 12 answers · asked by Smiler 3 in Science & Mathematics ➔ Biology
The answer is a few hundred to a few thousand (in humans).
Several people correctly identified the number of genes in *all* the strands of DNA in humans ... and other people focused on the number of strands ... but nobody (as far as I can tell) put the two together.
The human genome has about 25,000 to 30,000 genes.
And these are distributed over 46 chromosomes (strands of DNA). However, these are really 23 *pairs* of homologous chromosomes ... in other words both chromosomes in the pair contain the same genes ... the genes are duplicated.*
So that's 25,000-30,000 genes distributed across 23 *unique* strands.
So if we do the math, that is an average of about 1100 to 1300 genes per chromosome. Some chromosomes (like the Y chromosome) are shorter and some are larger, so some may have considerably less than 1100, while others are larger and may have a bit more than 1300.
[P.S. There are actually just 22 pairs of homologous chromosomes, and 1 pair of ... the sex-chromosomes ... that may or may not be homologous ... in males they are different (Y and X). But for purposes of estimation, I'm just considering the female case where this is just another homologous pair of X chromosomes.]
2007-09-20 04:02:37 · answer #1 · answered by secretsauce 7 · 5⤊ 0⤋
Genes or bases? Genes are strands of DNA that are transcribed into RNA which are translated into proteins (Entire process called the "Central dogma").
The length of DNA is measured by the number of bases not the number of genes as genes vary in length. As already stated Humans have around 30,000 genes, the number varies from animal to animal. The number of base pairs in Humans is 6,044,180,000 in a female and 5,947,010,000
in a male (Females have two X chromosomes and Males have one X and one Y Chromosome - the Y chromosome is far smaller than the X chromosome). These figures of course are approximate and do not include people with extra or fewer chromosomes e.g Down's Syndrome is caused by an extra chromosome.
2007-09-20 02:58:43 · answer #2 · answered by Anonymous · 1⤊ 0⤋
In humans, there about 30,000 genes even we have 3 billion base pair in DNA. Actually it's the prescence of such a large number of nucleotides in DNA that scientists initially tot there were about 100,000 genes in human. It's only after further research that they concluded there are only 30,000 genes, which is not much more than a fruit fly. Now it gets frustrating, because humans are complex, but fruit flies are just fruit flies. The answer to the complexity of humans probably lies in the sequences which does not code for a gene at all (non-coding gene). Shall save you from further torture. Read it up urself on that. Something along the lines of alternative splicing and regulatory sequences. :D
2007-09-20 02:51:35 · answer #3 · answered by Anonymous · 0⤊ 0⤋
in 2004 human genome sequence was lowered to be between 20000 - 25000 . those genes are put together in combinations to create proteins. in the human genome some of this genes are repeated many thousands of time, others only once . the entire human genome is about 3.2 billion base-pair . don't get confused by the genome and the number of genes , the genes are like alphabet characters the genome is like a book writing by those 26 characters.each of the human cells have about 6 feet of DNA stuffed into it and only about 1 inch is devoted to genes
2007-09-22 20:37:37 · answer #4 · answered by said n 1 · 0⤊ 0⤋
I think you've got it a bit sideways - I suspect what you meant to ask was "How many genes are contained in a chromosome?" to which the answer would be "It varies a lot, and the total number is not entirely certain even for organisms like humans whose genome we have basically determined." I'd settle for "lots", myself, but if you wanted an order of magnitude number, go with somewhere in the hundreds range.
2007-09-20 03:01:11 · answer #5 · answered by John R 7 · 1⤊ 0⤋
Genes are what the DNA molecule is divided into and from there the genes code for specific amino acids to make for the cell which are then made into proteins.
2016-05-19 01:44:34 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Er I think it varies from strand to strand. we have 46 strands each, I'm not sure how many genes there might be on a single strand.
EDIT: It's 23+23 and not 26+26 as stated above by prev poster...
2007-09-20 02:42:36 · answer #7 · answered by Anonymous · 0⤊ 1⤋
The number of human protein-coding genes was reduced in 2004 from 35,000 to between 20,000-25,000
2007-09-20 03:04:10 · answer #8 · answered by helen m 3 · 0⤊ 0⤋
Depends on which species you are looking at. Humans, I think, have around 30,000.
2007-09-20 02:40:01 · answer #9 · answered by Anonymous · 0⤊ 2⤋
Well, there's 54 chromosomes. Mommy's got 26 and daddy's got 26. Added together, in the fallopian tube, they make a little baby..... That silll blows my mind.... Anyhows..... Nah, I'm not sure, ....... I'l remember tonight.
2007-09-20 02:41:48 · answer #10 · answered by Anonymous · 0⤊ 5⤋