【单选题】A morphogen is
A.
a cell or group of cells that signal other cells to become determined in a specific way
B.
a gene that causes a cell or group of cells to adopt a particular shape
C.
a signaling molecule that causes the differentiation of neighboring cells
D.
a signaling molecule that confers concentration-dependent positional information
【单选题】Which of the following is true about them?
A.
They didn't have 20 years of communication.
B.
They come from the same country.
C.
They are husband and wife.
D.
Their stories were turned into novels
【单选题】Activin is a protein that normally exists in a gradient within certain tissues in developing embryos. Certain undifferentiated cells cultured without activin produce epidermal cells. However, activin ...
B.
cell-surface receptor.
【判断题】由于汽车行驶中,当车速一定时,空气阻力系数越大,则空气阻力消耗的汽车发动机功率就越小。
【单选题】如果用户想对某一命令详细的了解,可用()命令。
【判断题】如果用户想对某一命令详细的了解,可用man命令
【单选题】如果用户想对某一命令详细的了解,可用 。
【判断题】为缩短命令传达时间,调度命令内容简明扼要,尽量简化
【简答题】完形填空。 Last January I was given a chance to work in another country. At first, I lived a 1 life, but soon I met a group of new friends and they were really nice. Then something 2 happened. One of our f...
【单选题】在全面进行社会主义建设的过程中,毛泽东曾针对“大跃进”的“左”的错误,为把实事求是的精神恢复起来,号召全党( )