2006-10-21 05:09:56 · 14 answers · asked by cristina c 1 in Science & Mathematics ➔ Biology
46. 23 are inherited from each parent.
2006-10-21 05:12:06 · answer #1 · answered by PatsyBee 4 · 2⤊ 0⤋
Chromosome 21 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 21 is the smallest human chromosome (not counting the Y chromosome), spanning almost 47 million base pairs (the building material of DNA) and representing about 1.5 percent of the total DNA in cells.
In 2000, researchers working on the Human Genome Project announced that they had determined the sequence of base pairs that make up this chromosome. Chromosome 21 was the second human chromosome to be fully sequenced.
Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 21 likely contains between 200 and 400 genes.
You could get more information from the link below...
2006-10-21 21:42:02 · answer #2 · answered by catzpaw 6 · 0⤊ 0⤋
A rod-shaped structure, usually found in pairs in a cell nucleus, that carries the genes that determine sex and the characteristics an organism inherits from its parents.
A human body cell usually contains 46 chromosomes arranged in 23 pairs.
[Late 19th century. < German Chromosom < Greek khrōma "color" + sōma "body"; because chromosomes readily take up dye]
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2006-10-21 05:59:13 · answer #3 · answered by Scabius Fretful 5 · 0⤊ 0⤋
Number of chromosome pairs: humans 23
The smallest human chromosome is chromosome 21 (50 Mb) and the largest one is chromosome 1 (263 Mb). This is one reason why Down’s syndrome (trisomy 21) is the most common trisomy; the most tolerable of an intolerable condition (trisomies are the most common chromosome abnormalities in spontaneous abortions).
2006-10-21 05:19:23 · answer #4 · answered by veerabhadrasarma m 7 · 0⤊ 0⤋
The numbers given by others before are correct. The most dominant "Y" chromosome (female) or "X" chromosome (male) will determine the gender of the fetus.
2006-10-21 05:28:28 · answer #5 · answered by Oenophile... (Lynn) 5 · 0⤊ 0⤋
46 chromosomes
2006-10-21 05:13:17 · answer #6 · answered by Anonymous · 1⤊ 0⤋
the human karyotype has a total of 46 chromosomes arranged in matching.23 pair(diploid number)
2006-10-21 05:59:21 · answer #7 · answered by red devil 4 · 0⤊ 0⤋
Usually 46, but some have 44, 45, 47, 48....
2006-10-21 05:29:40 · answer #8 · answered by Wingaddict 2 · 1⤊ 0⤋
46 23 from each parent
2006-10-21 05:18:13 · answer #9 · answered by lilshorty3088 3 · 0⤊ 0⤋
44 & 2 or 46.
2006-10-21 05:17:10 · answer #10 · answered by Anonymous · 0⤊ 1⤋