螺甾烷醇和异螺甾烷醇二者互为异构体,常常是共存于植物体,且螺甾烷醇比异螺甾烷醇要稳定,因此异螺甾烷醇型易转化为螺甾烷醇型。()
参考答案:错
仔细观察下图:
(1)图一中的人物是谁?你如何评价他?
含草酸钙方晶的晶鞘纤维()
A.Bundles of partially lignified fibres with crystal sheaths
B.Numerous colourless single fibres, often whole with narrow lumen
C.Parenchymatous cells,fibres,and vessels
D.Starch granules present,fibres and sclereids absent
E.Fibres with crystal sheath containing calcium oxalate prisms