作者c20001222 (機哥)
看板medstudent
標題[申覆] 醫學二 97
時間Tue Feb 22 21:59:08 2011
[申覆] 醫學二 (97)
答案為A 申覆:AC 或 送分
出處:Robbins and Cotran Pathology Basis of Disease 8th edition p.287
In familial cases, children inherit one defective copy of the RB gene in the
germ line(one hit); the other copy is normal. Retinoblastoma develops when
the normal RB allel is mutated in retinoblasts as a result of spontaneous
somatic mutation(second hit). Because only a single somatic mutation is
required for loss of RB function in retinoblastoma families, familial
retinoblastoma is inherited as an autosomal dominant trait.
答案A:『由Rb 基因的單點突變所引起』,推測考試重點為"two hits theory",
然因無英文以供中英對照,
故"單點突變"、"點突變"、"單一點突變"之間,或有語意上混淆之嫌,
如選項改為類似『由Rb 基因唯一一個位置上的點突變所引起』等敘述法,
則或許較無題意模糊之疑慮。
且於familial cases中,其兩個異常alleles,一者為遺傳(one hit),
一者為後天突變(second hit),亦即先天有突變之allel只有其中一個位置,
也可作為答案A可行之佐證。
因上述原故,答案建議改為 送分 。
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◆ From: 61.231.26.40
※ 編輯: c20001222 來自: 61.231.26.40 (02/22 22:00)
推 Aramis:我覺得好像可以喔,因為後面寫著: "...they lose the intac 02/22 22:33
→ Aramis:t copy in the retinoblast through some form of somatic 02/22 22:34
→ Aramis:mutation(point mutation, interstitial deletion of 13q14 02/22 22:35
→ Aramis:or ever complete loss of normal chromosome 13). 02/22 22:35