I'm reading a book about genetics, but I'm really confused about chromosomes. It's mainly vocabulary trouble. It is my understanding that the human genome has twenty-three pairs of chromosomes. I commonly hear people say that humans have twenty-three chromosomes, does that mean chromosome types? Because if there are twenty-three pairs, then that would make forty-six, right? The book I'm reading is called The Language of Genes by Steve Jones. Here is the particular passage that's messing with me: "Every cell contains two copies of each of the chromosomes. The number is halved during a special kind of cell division in the testis or ovary. During the process, the chromosomes lie together in their pairs and exchange parts of their structure. Sperm or egg cells hence contain combinations of chromosomal material which differ from those in the cells of the parents who produced them." Now, when I first started reading this, I initially thought that when it said "every cell contains two copies," it was referring to chromosome pairs (two chromosomes of the same type; one from mom, one from dad). Then it says it halves, so we're left with twenty-three independent chromosomes. Then it says that the chromosomes lie together in their pairs, so then I went back and re-evaluated what it meant when it said "two copies," since based on my initial understanding, after it split in half, there would be no more pairs. So, now, my understanding is that there are forty-six chromosome pairs (which divide into the twenty-three chromosome pairs in the process from the quote). Which would now bring the count of individual chromosomes up to ninety-two. If I'm wrong (which I'm sure I am), please correct me. According to this picture (http://www.ncrtec.org/tl/camp/gene/male.gif), there are at least forty-six chromosomes (two times twenty-three). I'm totally confused by an apparent lack of clarity in what I'm reading (not clarifying whether it's about pairs of chromosomes or individual chromosomes, I'm just confused here). Chromosomes - This is another source I was using to clear my confusion. This site further reinforces my idea that there are forty-six. Can someone straighten me out here?