解析:The best answer is E. The first paragraph states that plant cells “differentiate and form structures” (line 3) when a “complex system of chemical messengers” (line 7) activates a “small subset of the genes in a particular kind of cell” (lines 5-6). In lines 38-41, the au...
17. Which of the following best describes Freshta Karim? A. Caring and courageous. B. Humorous and ambitious. C. Demanding and enthusiastic. D. Honest and hardworking. 相关知识点: 试题来源: 解析【答案】14.D 15.D 16.C 17.A 【解析】 【分析】这是一篇说明文。文章主要说明了27岁的牛津大...
This led them to believe that the cells in the early embryo are undetermined in the sense that each cell has the potential to develop in a variety of different ways. Later biologists found that the situation was not so simple. It matters in which plane the embryo is cut. If it is cut...
In the first place, most behaviors are governed by more than one gene, and until recently geneticists had no method for identifying the multiple genes involved. In addition, even when a single gene is found to control a behavior, researchers in different fields do not necessarily agree that ...
39. Which of the following correctly describes the role of stem cells in adult tissues and organs? D A Stem cells are undifferentiated cells found amongst differentiated cells and they take over the function of the tissue when the overlying cells become damaged or worn out. B Stem cells are ...
According to the passage, which of the following best describes a function performed by oligosaccharins? 选项: A、Regulating the daily functioning of a plant's cellsInteracting with one another to produce different chemicals B、Releasing specific chemical messengers from a plant's cell walls C、Pro...
Studying the DNA of 300 mice has flagged up (引起注意) genes which have been linked to hereditary (遗传的) sight loss for the first time. Researchers say because mice’s genes are so similar to humans’, their findings could lead to the treatment of more genetic diseases. Scientists at ...
was glad with the way things had progressed.His robot looked even better than Alicia’s and it was able to bounce a ball with its arm, something Alicia had failed to do.On the day of the competition, he saw Alicia.Everything dawned on her the minute she sawhim among the competitors. ...
Which of the following best describes the purpose ofthe sentence in highlight (“What is … Jamaica”)? A. It raises a question about why coexisting anole lizard species occupy the different types of habitats mentioned in the first sentence. B. It introduces a fact about anole lizard ...
According to the passage, which of the following best describes a function performed by oligosaccharins? A. Regulating the daily functioning of a plant’s cells B. Interacting with one another to produce different chemicals C. Releasing specific chemical messengers from a plant’s cell ...