Oxygen (O2) makes up about 21% of the Earth's atmosphere. The graph below depicts changes in atmospheric O2 levels measured between the years 1990 and 2008. During what season would you expect oxygen levels to be lowest in a single year?
A. summer
B. fall
C. winter
D. spring
D
Biology & Microbiology
You might also like to view...
A hot tub (approx. 104?F or 40?C) would most likely contain
A. psychrophiles. B. partiers. C. thermophiles. D. mesophiles.
Biology & Microbiology
____ is/are considered to be the ancestor to both Homo neanderthalensis and Homo sapiens
a. Homo habilis b. Paranthropus loisei c. Homo floresiensis d. Denisovians e. Homo erectus
Biology & Microbiology
The area of Earth that supports life is known as the ____
a. atmosphere b. biosphere c. hydrosphere d. lithosphere e. stratosphere
Biology & Microbiology
The internal urinary sphincter is made of __________ muscle and under __________ control.
A. skeletal, voluntary B. skeletal, involuntary C. smooth, voluntary D. smooth, involuntary
Biology & Microbiology