伴性遗传.ppt

e to study biology !
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翔宇教育集团宝应中学朱学梅
第2节伴性遗传
翔宇教育集团宝应中学朱学梅
1、有一对表现型正常的夫妻生了一个白化病的孩子,则他们下胎生儿子患白化病的概率为,生女儿患白化病的概率为
2、有一对表现型正常的夫妻生了一个患色盲的孩子,则他们下胎生儿子患色盲的概率为,生女儿患色盲的概率为。
1/4
1/4
1/2
0
思考:两题的概率为何不一样?
伴性遗传概念
位于性染色体上基因所控制的性状的遗传常常与_____相关联
性别
红绿色盲
It is Chrismas bought my mother
a pair of “grey socks”.
-- Dalton:Mum,it is for you.
-- Mum:Oh,my god!The cherry red socks
you bought me are so colorful that I
could not wear them!
I was thought the socks were clearly grey,why did mum say cherry red?So I asked my bother and people the people,except my brother and I,said those socks were cherry ,I found my brother and I had a different sense of called the disease”color blindness”.I was the first person who found the disease,and I wrote a paper about “color blindness”.
[Reading DIY]
家族之谜
analyze the transmission pattern of the disease
[探究]
红绿色盲是____染色体上的____性遗传病
X
隐
道尔顿的家庭
XY
XX
XX
XY
XX
XY
道尔顿
道尔顿弟弟
X
男性患者
女性患者
表现型
基因型
男性
女性
XbY
XBY
XBXB
正常
XBXb
正常
携带者
XbXb
色盲
正常
色盲
6种婚配方式= 女3种基因型 x 男2种基因型
人的正常色觉和红绿色盲的基因型和表现型
假设色觉正常为XB ,色盲为Xb
男女6种婚配方式
XBXB
XBY
x
1
2
3
5
4
6
XBXb
XBY
x
XbXb
XBY
x
XBXB
XbY
x
XBXb
XbY
x
XbXb
XbY
x
无色盲
男:50% 女:0
男:100% 女:0
男:50% 女:50%
都色盲
特点1:男>女
无色盲