@oristarA,
hmmmm.. it's more complicated than that, ori. Taking it from the top (macro) down to the specific (micro) you have
the human genome -- a complete mapping of the 25,000 or so genes that make up the human profile.
next in order is the chromosome -- 46 total, in pairs -- one set from each parent. There are 23 chromosome pairs, one of which is the sex chromosome containing X and/or Y chromosomes (one on each of the pair). Females carry an XX pair (and can therefore only pass on the X sex chromosome to their offspring), while males carry the XY pair and can pass on either the X chromosome or the Y chromosome to their offspring. Gender is determined by which chromosome is carried by the particular sperm that fertilizes the X egg.
Genes are the structures that contain the info needed to make the things we need to make to survive, especially proteins. As I said above, we each have about 25,000 genes bundled onto the 23 chromosome pairs. But a gene is only a portion of the cell's DNA.
The DNA is what carries the genetic material that drives everything above it. DNA is made up of four chemicals, called bases, which are repeated over and over in strands.
So--- looking at your second sentence
Quote:A given cell's DNA spends most of its active lifetime in a tangled clump of chromosomes, which positions groups of related genes near to each other and exposes them to the cell's gene-controlling machinery. This structure, the researchers say, is not merely the shape of the genome, but also a key to how it works.
The use of the word "chromosomes" is related to all 23 pairs.
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