High levels of ____ could indicate life on other planets
a. free nitrogen
b. carbon dioxide
c. free oxygen
d. bound nitrogen
ANS: C
Oxygen in itself is a very reactive element. It binds quickly to other materials. Remember, free oxygen
only became abundant in our atmosphere when photosynthetic organisms began producing more.
Thus, if there is a large amount of free oxygen, then there is something present that is replacing it in
the atmosphere. This is likely to be a life-form of some sort. Information can be found in the section
Are There Other Ocean Worlds
You might also like to view...
Globalization of the last 3-4 decades is characterized by a significant increase in all of the following except
A) the transnational scope of global economic and cultural activities. B) the expansion and intensification of linkages and flows of capital, people, goods, ideas and cultures across national borders. C) the influence of transnational rules and organizations. D) the importance of local communities and national governments. E) both the influence of transnational rules and organization and the importance of local communities and national governments.
Which of the following industries is most responsible for deforestation in the world?
A) Farming for animal and crop production B) Housing construction C) The lumber mills and wood pulp manufacturing D) Hydroelectric plants
Which of the following sites would have the most dangerous volcanoes? A is on an island arc, B is in the Andes, C is near Hawaii, D is along a mid-ocean ridge.
A. A and B B. A and C C. B and C D. B and D E. C and D
To calculate sea-level pressure everywhere, we need to correct for:
a. differences in elevation. b. differences in temperature. c. differences in wind speed. d. differences in relative humidity.