染色體的問題~

2008-01-26 5:37 am
據我所知人體有23對染色體....
23對染色體控制人體什麼?
XX是女性.XY是男性.XYY是超級男性.
.有超級女性嗎?其特徵是什麼?

回答 (3)

2008-01-26 5:45 am
✔ 最佳答案
一.人體約由500億個細胞組成,每個細胞中心都有細胞核,每個細胞核包含有23對染色體,分別承繼父母的遺傳物質,每個染色體都包含有雙螺旋狀的DNA分子,帶有遺傳因子的基因排列在DNA雙螺旋梯上。
二.第21對染色體有225個基因,已辨識出127個已知基因,已確定其中103個基因的功能,另有98個基因完成部分的辨識工作,己得知其中14個基因為遺傳性疾病的起因。
三.人體每個細胞裡都有23對染色體,在染色體上原粗估承載了十萬個基因,這些基因的基本構成單位即是DNA,基因的組成和運作用方式決定了我們的高矮胖瘦,是否容易生病或衰老等遺傳特質。每個基因由四種密碼序列組合而成的,這四種密碼代號被訂為"A,G,T,C",每種代碼都是一種鹼基。一組完整的人體DNA,便是由30億個鹼基對組成。
科學家企圖將這三十億個鹼基對的順序正確無誤地排出來,並清楚標記它們在染色體上的位置,稱為人類基因圖譜。
四.基因組是組成內含生命指令的去氧核醣核酸(DNA)的基因組合,基因是由鹼基對構成的群組(鹼基對是基因組成的基本單位),每個基因就是構成一個生命的單一指令;人類基因圖譜共有約三十一億二千萬對遺傳密碼之鹼基對,構成三萬五千到四萬個基因。
五.在人類十萬個基因當中,約有一萬個是能夠製造蛋白質的功能基因,科學家能掌握的只有四百到六百個,如生長激素和胰島素是由特定功能基因製造出來的,還有九千多個待研究。
六.人類基因,現在仍有97%功能未知
[1]構成人體細胞總數約為500億個,每個細胞裡都有30億個字母排列組成的DNA密碼。每個細胞中的DNA長達6呎,但擠在一個直徑只有0.0004吋的結構中。
[2]組成DNA的四個字母"A,G,T,C"攜有構成一切有機體的密碼,以三個字母為一組,搭配一種胺基酸。

XYY三體是一種人類男性的性染色體疾病,正常的男性性染色體是XY,而XYY三體者多出一條Y染色體﹐所以又稱超雄綜合症。
此病在各種性染色體疾病中比較常見,在男性新生嬰孩的發病率是1/500到1/1000。患者身材高大,痤瘡嚴重,有些病例會骨骼畸形、智能障礙。患者的睪酮水平不會特別高。
XYY 的病因是由於父親精子形成時發生問題。問題發生在減數分裂偶線期II時,便會使精子細胞有兩條Y染色體。若該顆精子和卵子結合,胚胎細胞便會有2條Y染色體。


Klinefelter's syndrome, 47, XXY or XXY syndrome is a condition caused by a chromosome aneuploidy. Affected males have an extra X sex chromosome. The principal effects are development of small testicles and reduced fertility. A variety of other physical and behavioral differences and problems are common, though severity varies and many boys and men with the condition have few detectable symptoms. The second most common extra chromosome condition, it is named after Dr. Harry Klinefelter, an endocrinologist at Massachusetts General Hospital, Boston, Massachusetts, who first described it in 1942.[1] The condition exists in roughly 1 out of every 500 to 1,000 males.[2] Because of the extra chromosome, individuals with the condition are usually referred to as "XXY Males", or "47,XXY Males".
2008-01-28 3:34 pm
Yes there is super female.
Triple X syndrome occurs in 1 in 1,000 newborn girls. On average, five to ten girls with triple X syndrome are born in the United States each day.

Females with the condition are usually taller than average, and their weight may be low in comparison to their height. They may have menstrual irregularities, and, although rarely exhibiting severe mental impairments, have an increased risk of learning disabilities, delayed speech, and language skills.
2008-01-26 8:03 pm
性別
XXX(笑)
假設一下
XX是女性.XY是男性.XYY是超級男性
各減一個x
得X是女性.Y是男性. YY是超級男性!
XX是超級女性
加番x
soXXX是超級女性xd


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