The dilemma of whether proteins or nucleic acids directed the first synthesis of the other is avoided by the
A. protein-first hypothesis.
B. RNA-first hypothesis.
C. clay-catalyst hypothesis.
Ans: C. clay-catalyst hypothesis.
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The energy of electron transport serves to move (translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion produce ATP?
A) The hydrogen ions (protons) are transferred to oxygen in an energy-releasing reaction. B) The translocation of protons sets up the electrochemical gradient that drives ATP synthesis in the mitochondria. C) The protons pick up electrons from the electron transport chain on their way through the inner mitochondrial membrane. D) The protons receive electrons from the NAD+ and FAD that are accepted by electrons in glycolysis and the citric acid cycle.
Current evidence suggests that
A. the "Big Bang" occurred about 13 billion years ago. B. atoms from the "Big Bang" collected into stars and planets. C. the Earth formed about 4.6 billion years ago. D. All of these answers are correct.
Which of the following most directly gives rise to primary vascular tissues?
a. protoderm b. apical meristem c. ground meristem d. vascular cambium e. procambium
Which of the following groups were first to
have an amniotic egg?
a. birds b. reptiles c. amphibians d. bony fishes e. mammals