Approximately when did the earth's crust solidify?

A) 8 billion years ago
B) 4 billion years ago
C) 2 billion years ago
D) 1 billion years ago


B

Biology & Microbiology

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Glycogen is a polysaccharide used for energy

storage by

a. plants. b. animals. c. protists. d. bacteria. e. archaea

Biology & Microbiology

Birds are most closely related to

A. crocodiles. B. snakes. C. mammals. D. non-avian dinosaurs. E. amphibians.

Biology & Microbiology

Bacteria able to perform the NH4+ + NO2- ? N2 + 2H2O reaction have been discovered in laboratory bioreactors and wastewater treatment systems. Researchers predicted that these bacteria should exist in oceans

They measured the concentration of NH4+, NO2-, NO3-, and O2 in the Black Sea as a function of water depth (M. Kuypers et al. 2003 Anaerobic ammonium oxidation by anammox bacteria in the Black Sea. Nature 422:608-11 ) to determine where in the sea the bacteria might live. Analyzing data presented in the figure above, at what depth would you expect to find the bacteria? (Note: In the figure, different scales are used to show concentrations of NH4+, NO2-, NO3-, and O2.) A) in the top 50 meters B) at a depth of 75 meters C) at a depth of 92 meters D) below 100 meters

Biology & Microbiology

Hagfishes have three-chambered hearts, which improve gas exchange with the lungs

Indicate whether the statement is true or false

Biology & Microbiology