When oxygen became part of the atmosphere, it came from
A. carbon dioxide.
B. volcanoes.
C. the splitting of water by autotrophs.
D. organic molecules.
C. the splitting of water by autotrophs.
You might also like to view...
The muscles of the anterior leg compartment work synergistically to __________ the foot.
a. invert b. rotate c. dorsiflex d. plantar flex
According to the phylogeny shown below, which of the following is a synapomorphy of ascomycetes and basidiomycetes?
A. regular septa B. complex, multicellular fruiting bodies C. chitin in cell walls D. hyphae E. All the answer options are correct.
The cytoskeleton ____
a. extends between the nucleus and the plasma membrane b. is found within the nucleus c. is associated with only certain cell structures d. is found within organelles e. is found in all animal cells but not in cells with cell walls
Spliceosomes are composed of _____.
a. small RNAs and proteins b. polymerases and ligases c. introns and exons d. the RNA transcript and protein