The increase in atmospheric oxygen during the Proterozoic was most related to the ____
A)decrease in global volcanism
B)decrease in ocean sizes
C)process of photosynthesis by bacteria
D)appearance of land plants
E)origin of complex life forms
C
You might also like to view...
Which of the following is not a "hard" shoreline protection measure?
A) groins. B) beach nourishment. C) jetties. D) breakwater.
Climates in the past were much the same as they are today
Indicate whether the statement is true or false
If a molecule of human DNA were fully stretched out approximately how long would it be?
A) 1 mm B) 1 cm C) 1 m D) 5 m
Oceanic crust is denser than continental crust because ____
a. ?continental crust stands at a higher altitude b. ?oceanic crust is rich in silica c. ?oceanic crust is compressed at convergent boundaries d. ?water pressure from the oceans makes oceanic crust thinner e. ?oceanic crust is rich in iron- and magnesium-containing minerals