In article <38d6daa3.646002714 at news.starpower.net>,
carlewis at starpower.net wrote:
> Hi
>> Im a non-specialist reporter working on a story about the genome. Im a
> little wary on numbers here. Is this an accurate description of a
> genome.
>> "....the entire human genome, or the complete set of human genes
> strung out along 23 chromosomes, some 3 billion separate bits of
> genetic information."
>> Or should I describe it as "the complete set of human genes strung
> along 23 PAIRS of chromosomes or some 6 billion seperate bits of
> genetic infomation.
>> Any advice would be helpful
>> Julie
>>
23 pairs of chromosomes are in somatic cells, or 23 chromosomes in germ
(egg or sperm cells) in humans. Somatic (i.e., non-reproductive) cells
are said to be "diploid," whereas germ cells are "haploid."
There are 3 billion (US usage, i.e., 3 thousand million) nucleotide pairs
(note that DNA in the genome is double stranded) per haploid genome. To
oversimplify, each nucleotide pair can be considered to be one "bit" of
genetic information (a lot of it is beleivedto be "junk," however).
Whether you describe the DNA content of a diploid or a haploid cell is
somewhat a matter of context and semantics.
--
_______________________________________________
Nick Theodorakis
nicholas_theodorakis at urmc.rochester.edu
Sent via Deja.com http://www.deja.com/
Before you buy.
