Which of the following is common to the carbon cycle, the nitrogen cycle, and the water cycle?
O These substances are required by living things and are involved in many processes that
occur in living things.
O The substances must pass through only organisms in order to complete their cycles.
The substances are rearranged into different types of molecules as they move through
their cycles.
cycles. The largest stored amounts of these substances are always in organisms.

Abacteriophage typically attaches to the bacterium and then

How do high-energy electrons from glycolysis and the krebs cycle contribute to the formation of atp from adp in the electron transport chain? a. high-energy electrons interact with pyruvic acid to create a phosphate bond with adp, forming atp. b. high-energy electrons supply the needed energy to synthesize atp from the lower-energy adp in the electron transport chain. c. high-energy electrons supply a negative charge which causes the citric acid to oxidize, forming a phosphate group to bond with adp. d. high-energy electrons increase the temperature of adp so it easily reacts to form atp.

Our planet has experienced five major extinctions in the four billion year history of life. the first, 450 million years ago, occurred shortly after the evolution of the first land-based plants and 100 million years after the cambrian explosion. the second extinction occurred 350 million years ago, causing the formation of coal forests. next earth experienced two mass extinctions during the triassic period, between 250 and 200 million years ago. the fifth mass extinction occurred 65 million years ago, ending the reptilian dominance of the earth. according to richard leakey, the sixth mass extinction is happening right now. leakey suggests that we, the human race, are the cause. each year, at our hand, approximately 50,000 species vanish from earth. he believes that man is destroying earth at a rate comparable with the impact of a giant asteroid. leakey's statistics indicate that 50% of earth's species will become extinct within the next 100 years assuming leakey's hypothesis of a sixth mass extinction to be true, how will we expect the model to change? a) a sharp spike in the graph approximately 100 million years from now b) a dip in the graph, followed by a sharp spike about 100 million years from now c) a sharp spike in the graph immediately following the "0" location of the x axis d) a plateau following the "0" mark on the x axis, followed by a gradual rise to a new peak