Explain why mitosis has to come before cytokinesis in the cell cycle.The chromosomes must be corrected divided up and the nucleus duplicated before the actual cell can divide into two new cells. Why is it important for mitosis to occur?
They get shorter each time a cell divides,until a cell cannot divide any more and dies.可知,端粒是特殊的DNA 的序列,可以阻止染色体中的DNA 分裂。每次细胞分裂时,它们都变得更短,直到细胞不能分裂任何一个细胞。可知,"they"指的是Telomeres.故选A. (3)D.推理判断题。由第六段Telomeres shortened ...
They get shorter each time a cell divides, until a cell cannot divide any more and dies. Several factors have been found to shorten telomeres including smoking, radiation (辐射) and psychological stress(心理压力), such as being treated badly when young, and taking care of someone who is ...
dreaming of…… The letter was written in French. The letter was from my pen pal in Paris. → The letter……., being from…… 分詞構句的作用 分詞構句可用來表示各種不同的目的,常見的有以下幾種: A. 表示「事件發生的先後順序」 After she washed the dishes, Marian made a pot ...
Telomeres are special DNA sequences which prevent the DNA in chromosomes from separating. They get shorter each time a cell divides, until a cell cannot divide any more and dies. Several factors have been found to shorten telomeres, including smoking, radiation and psychological stresses such as ...
C. hardship can change a child’s aging D. hardship has a long-term effect on children 2.According to the text telomeres ___. A. probably cause a cell to divide quickly B. can help prevent DNA from separating C. can make a cell die quickly D. become shorter before they die 3.All...
They get shorter each time acell divides, until a cell cannot divide any more and dies.Several factors have been found to shorten telomeres, includingsmoking, radiation and psychological stresses such as being treatedbadly when young and taking care of a longtime sick person.In this study, ...
根据第二段中 "… by studying the ends of children's chromosomes(染色体), called telomeres" 可知D项错误;根据第三段中 " They get shorter each time a cell divides, until a cell cannot divide any more and dies." 可知A、C项错误。 (3) 考查细节理解。根据第四段 "Several factors have been ...
s chromosomes(染色体), called telomeres,科学家们通过研究孩子们的染色体的末端来检测,可知A错误;根据第三段中的They get shorter each time a cell divides, until a cell cannot divide any more and dies每次一个细胞分化就会变得更短,直到细胞不能再次分化并死亡。.可知C、D错误。故选B 3. 推理判断题。
Can a cell make mRNA without the DNA in the nucleus? Fill in the blank: Cytokinesis begins with the formation of an indentation around the cell called the ___. Which of the following is the genetic information found in the nucleus of the cell (like the ...