作者rbhank30 (X)
看板Biology
標題[問題] campbel0e testbank Ch32 26題請高手解惑
時間Mon Mar 3 15:20:16 2014
【問題】：第26題的本文如下:
Trichoplax adhaerens(Tp) is the only living species in the phylum Placozoa.
Idividials are about 1 mm wide and only 27 um high, are irregularly shaped,
and consist of a total of about 2000 cells, which are diploid(2n=12). There
are 4 types of cells, none of which are nerve or muscle cells, and none of
which have cell walls. They move using cilia, and any "edge" can lead.
Tp feeds on marine microbes, mostly unicellular green algae, by crawling
atop the algae and trapping it between its ventral surface and the substrate.
Tp sperm cells have never been observed, nor have embryos past the 64-cell
(blastula)stage.
26. On the basis of information in the paragraph above, which of these should
be able to be observed in Tp?
<A> the act of fertilization
<B> the process of gastrulation
<C> eggs
<D> all three of the listed responses are correct.
【個人看法】：因為沒有精子,因此A選項先刪除, 而又沒有blastula stage 因此覺得
B選項也不太可能。剩下C，也就是答案給的正確選項，但是不知道原因為何，依題
目中的描述，我認為該生物應該行無性繁殖，且沒有少於64細胞的胚時期，有可能是行
出芽,斷裂,或分裂, 因此為何答案會是egg不解?麻煩請各位高手大大幫忙解惑,感激不盡
【參考資料/連結】：
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1F：推 qiet:既然有所謂的embryo, 不是就代表有egg(卵)? 03/03 20:51
2F：→ qiet:還有那句話應該是指說胚時期過不了64個細胞的stage 03/03 20:52
3F：→ qiet:所以會有個受精卵曾經被觀察到可以發遇到64-cell stage 03/03 20:52
4F：→ rbhank30:感謝解答! 很棒的解釋,我了解了~! 03/04 15:37