蛋白质的二级结构是指本省盘曲或折叠形成的局部空间构象,主要有()是结构。
参考答案:α螺旋和β片层
按括号内的要求改写下列各句。
1. Tom thinks they are scary. (改为否定句)
Tom _____ _____ they _____ scary. .
2. Her cousin likes thrillers. (就划线部分提问)
_____ _____ of _____ does her cousin like?
3. I want to see a movie. (改为同义句)
I want _____ _____ _____ a movie.
4. My favorite movie star is Jack Chan. (就划线部分提问)
_____ _____ your favorite movie star?
5. I like movies and I like Beijing Opera. (改为简单句)
I like movies _____ _____ _____.
6. She doesn't like to see movies. (改为肯定句).
She _____ _____ movies.
如图为在光学显微镜下看到的植物细胞模式图,因为该细胞有______、______和______.
(1)刀切鲜橙时,流出的黄色汁液主要是______,它来自图中结构[______]______.
(2)能够控制物质进出细胞的结构是[______]______.
(3)对细胞具有保护作用的结构是[______]______.
(4)[______]是绿色的,其体内含有______.