现代进化理论认为,突变和基因重组产生生物进化的原材料,下列哪种变异现象不属于此类

题型:选择题

问题:

现代进化理论认为,突变和基因重组产生生物进化的原材料,下列哪种变异现象不属于此类突变的范畴 [ ]

A.黄色×黄色→黄色、绿色

B.红眼果蝇中出现了白眼

C.猫叫综合征

D.无籽西瓜

考点:基因突变基因重组染色体变异
题型:选择题

Do you know S.H.E.? It is a singing group(歌唱组合) from Taiwan, China. Three girls are in it. They are Selina, Hebe and Ella. Their Chinese names are Ren Jiaxuan(Selina), Tian Fuzhen(Hebe)and Chen Jiahua(Ella).

Look! Here is a photo. Selina is very nice. Her hair is long. She is not short and not tall. Ella looks like a boy. She is medium build(中等身材). She has short hair. She is cool! Hebe is a nice girl. She isn’t tall. She is medium build, too. Her hair is not long.

根据短文内容,完成下列句子,每空一词。(5分)

小题1:Here is a ________ of S.H.E.

小题2:S.H.E is from ________.

小题3:Ren Jiaxuan is Selina’s English ________.

小题4:Selina’s hair is ________.

小题5:Ella looks like a ________. She is cool!

题型:选择题

酸性矿灯蓄电池()调整一次电解液的相对密度。

A、每月

B、每两月

C、每半月

D、每3个月

题型:选择题

生活中的下列现象,属于化学变化的是(  )

A.海水晒盐

B.湿衣服晾干

C.海水制碱

D.玻璃破碎

题型:选择题

与相同公称尺寸的三角形粗牙螺纹相比,三角形细牙螺纹()。

A.自锁性好,螺杆强度高

B.自锁性好,螺杆强度低

C.自锁性差,螺杆强度高

B.自锁性差,螺杆强度低

题型:选择题

下列电光源中有效寿命最长的是().

A.白炽灯

B.卤钨灯

C.高压钠灯

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