6. Which of the following elements is likely to form the least polar covalent bond with hydrogen?

A. Nitrogen
B. Oxygen
C. Carbon
D. Phosphorus

7. The mitochondria were known in the nineteenth century to be osmotically active on the basis of evidence that

A. the mitochondrial matrix is hypotonic to the cellular cytoplasm
B. the mitochondrial matrix is hypertonic to the cellular cytoplasm
C. mitochondria were derived from a symbiotic bacterium
D. mitochondria are surrounded by a semi-permeable membrane

8. Mitochondria can be expected most numerous in

A. green cells
B. red blood cells
C. muscle cells
D. none of these

9. Why do some redox reactions in cells result in the transfer of electrons from a reductant with a higher standard redox potential to an oxidant with a lower standard redox potential?

A. Redox potentials are defined under standard conditions, and cellular conditions are typically not standard conditions
B. The rules governing oxidation and reduction apply only in vitro, and not in vivo
C. Electrons always go from reductants with high redox potentials to oxidants with low redox potentials
D. None of the above

10. Lysosomes are associated with

A. photosynthesis
B. respiration
C. storage
D. digestion