34. 如果將 MPF(maturation-promoting factor)注射到 G2 細胞週期的蛙卵母細胞,下列敘述何者
最為正確?
(A) 什麼事都不會發生
(B) 卵母細胞開始減數分裂
(C) 卵母細胞開始細胞分裂
(D) 卵母細胞開始分化
答案:登入後查看
統計: A(46), B(254), C(935), D(93), E(0) #1727000
統計: A(46), B(254), C(935), D(93), E(0) #1727000
詳解 (共 10 筆)
#3561035
●我的想法是 : mitosis跟meiosis都有G2期,所以
重點是題目寫蛙卵母細胞,等於下面解釋的卵原細胞。
另外,大家疑惑的問題應該是名詞定義問題:mitosis, which is the division of the nucleus and its contents, and cytokinesis, which the the division of the cell as a whole.
所以mitosis除了可以指有絲分裂,還有核分裂的意思。減數分裂也有核分裂的過程,跟定義並不衝突(螢光部分)。
●Maturation-promoting factor (abbreviated MPF, also called mitosis-promoting factor or M-Phase-promoting factor) is the cyclin-Cdk complex that was discovered first in frog eggs. It stimulates the mitotic and meiotic phases of the cell cycle. MPF promotes the entrance into mitosis (the M phase) from the G2 phase by phosphorylating multiple proteins needed during mitosis. MPF is activated at the end of G2 by a phosphatase, which removes an inhibitory phosphate group added earlier.
●在卵細胞發育過程中,一個卵原細胞首先經過有絲分裂進行複製產生一個初級卵母細胞;隨後初級卵母細胞通過減數分裂產生次級卵母細胞與第一極體;接下來次級卵母細胞繼續進行減數分裂產生卵細胞和第二極體,同時第一極體也進行一次減數分裂成為兩個極體(注意,哺乳動物的第一極體一般不會進行減數分裂,所以一共只會產生第一極體和第二極體這兩個極體)。最終,三個極體(哺乳動物只有兩個極體)消失,只留下卵細胞。
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#3356142
各位同學們@@
Campbell確實是寫mitosis而不是meiosis

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#5442339
有點刁專啊這題,覺得沒出好又剛好沒人申訴吧
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