题目内容

Blue-green bacteria such as single-celled Gleocapsa and multicellular Nostoc contain chlorophyll arranged in nonmembranous layers inside their cells as shown above. Based on the diagrams shown above, what is a reasonalbe conclusion that can be reached about the relationship between the two structures represented?

A. The two stuctures evolved independently of one another.
B. It is likely that chloroplasts and blue-green bacteria are descended from a common ancestor.
C. Blue-green bacteria are free-living chloroplasts.
D. Chloroplasts evolved to be better blue-green bacteria.

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Temperature-dependent sex determination (TSD) involves a process in which the temperature of the embryo's environment influences its sex development into a male or female. One cause of TSD is the enzyme aromatase. It converts sex steroids from male sex hormones to female hormones. Reptiles, such as turtles and crocodiles, exhibit temperature-dependent sex determination. During the thermosensitive period, if the temperature increased then there would be higher levels of aromatose activity. Which of the following can be concluded from the diagram?

A. The Sox9 gene indirectly regulates aromatase activity.
B. The activation of FoxL2 gene indirectly initiates aromatase expression.
C. The uptake of estradiol will result in the increased release of testosterone.
D. The temperature required to produce female offspring is significantly lower than the temperature to produce male offspring.

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The graph shows the amount of DNA in a cell over several days. What can be concluded about the process occurring at label D?

A. DNA replication
B. gap period of rest
C. meiosis
D. mitosis

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程序完善题：求变量a、b、c中的最大值。请补充完整：Dim max as Integerif a>b then Else End if

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程序完善题：从键盘上任意输入10个整数，然后从中查找出最大数并显示出来，事件代码如下：Private Sub s1() Dim A(1 to 10) as IntegerDim Max As Integer‘从键盘输入10个整数For i=1 to 10 A(i)=InputBox(“请输入第”& str(i) & “个数据：”, “输入数据”)Next i ‘从10个数中查找出最大的数Max=A（1） ‘先假设数组中第一个数据最大 __ ‘显示查找的结果MsgBox “最大值为：”& MaxEnd Sub

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A. The two stuctures evolved independently of one another. B. It is likely that chloroplasts and blue-green bacteria are descended from a common ancestor. C. Blue-green bacteria are free-living chloroplasts. D. Chloroplasts evolved to be better blue-green bacteria.

The graph shows the amount of DNA in a cell over several days. What can be concluded about the process occurring at label D?

程序完善题：求变量a、b、c中的最大值。请补充完整：Dim max as Integerif a>b then ______ ______ ______ ______ ______ Else______ ______ ______ ______ ______ End if

A. The two stuctures evolved independently of one another.
B. It is likely that chloroplasts and blue-green bacteria are descended from a common ancestor.
C. Blue-green bacteria are free-living chloroplasts.
D. Chloroplasts evolved to be better blue-green bacteria.

程序完善题：求变量a、b、c中的最大值。请补充完整：Dim max as Integerif a>b then Else End if