题目内容

During the investigation, the lights are turned off after 15 hours. What will occur to the dissolved oxygen concentration?

A. The dissolved oxygen concentration in both flasks will remain constant.
B. The dissolved oxygen concentration in the flask containing Elodea will be reduced.
C. The dissolved oxygen concentration in the flask containing Elodea will be increased.
D. The dissolved oxygen concentration in the control flask will be increased.

查看答案

搜索结果不匹配？点我反馈

更多问题

The student further investigated the dissolved oxygen concentration by varying the light intensity. Which of the following graphs most likely represent the data from his new investigation?

A
B
C
D

查看答案

Based upon the results from his experiment, what was Engelman able to conclude regarding the relationship between the wavelength of light and the rate of photosynthesis?

A. The photosynthetic rate is highest at 500nm.
B. The photosynthetic rate is highest in blue light.
C. The photosynthetic rate is highest in red and violet light.
D. The photosynthetic rate is highest in 650nm.

查看答案

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.

查看答案

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.

查看答案